The Boiler Control 275 is designed to stage up to four condensing or non-condensing, modulating or on-off boilers using
P.I.D. staging to accurately maintain temperature. The control supports hybrid boiler plants that contain both condensing
and non-condensing boiler groups. Water temperature is controlled by outdoor reset for space heating applications or a
fixed setpoint for Domestic Hot Water (DHW) tank heating or industrial process heating applications. The control will also
accept an analog signal from an Energy Management System (EMS) to control the water temperature. Boiler equal run-time
rotation, pump exercising and stand-by system pump operation increase boiler plant reliability. The control is tekmarNet®
communication compatible allowing for internet connectivity using an optional Gateway 483.
Additional functions include:
tN4 Compatible
•
BTC I Compatible
•
24 Hour, 5-11, 5-2, 7 Day Schedule
•
Flow or Combustion Air Proof
•
Four Modulating or On/Off Boilers
•
Equal Run Time Rotation
•
Primary Pump Sequencing
•
DHW Operation
•
Optional DHW Sensor
•
Setpoint Operation
•
tN4
Boiler
Bus
MenuItem
Boiler Control 275
One tN4, Four Modulating Boiler & DHW / Setpoint
Do not apply power
2
1
tN4
–
5
3
4
6
7
8
BRet/
Mod1
Com
Out10Com
Boil
+
DHW
Sup
Mod2
+
–
12
9
11
Mod3
Mod4
+
+
+
–
Boiler Demand
DHW / Setpoint Demand
Proof Demand
Zone Load Shedding
Priority Override
EMS Input Signal
Relay1Relay2Relay3Relay4C.A. /
Setback
Off
Exercise
Rotate
BTC I
Off
EMS
Demands
Test
Designed and assembled in Canada by
tekmar Control Systems Ltd
tektra 1020-01
Power 115 V ±10% 60 Hz 7 VA, 1150 VA max.
Relays 230 V (ac) 5 A 1/3 hp
Demands 20 to 260 V (ac) 2 VA
Signal wiring must be rated at least 300 V.
26
Alert
2325161518172 0192221
DHW
/ P2
24
Prim
Power
P1 L N
Boiler
Demand
28271413
Pump Sequencer
Fixed Last
Fixed Lead
First On / Last Off
First On / First Off
off
red
red
For maximum heat,
press and hold Tes t
button for 3 seconds.
This brochure is organized into three main sections.
They are: 1) Sequence of Operation,
2) Installation,
3) Control Settings and
4) Testing and Troubleshooting.
Table of Contents
The Control Settings section of this brochure describes
the various items that are adjusted and displayed by the
control. The control functions of each adjustable item are
described in the Sequence of Operation.
User Interface ...............................................................2
Display and Symbol Description ................................... 3
Section M: Combustion Air and Alert Settings ....... 18
Section N: Setting the Schedule ............................ 19
User Interface
The control uses a Liquid Crystal Display (LCD) as the
method of supplying information. You use the LCD in
order to setup and monitor the operation of your system.
The control has four push buttons (Menu, Item, ▲, ▼) for
selecting and adjusting settings. As you program your
control, record your settings in the ADJUST menu table,
which is found in the second half of this brochure.
Section O: Time Clock ...........................................20
releasing the Item button will return the display to the first
item in the selected menu.
The items can be quickly scrolled through by holding the
Item button and then pressing the ▼ button. To rapidly
scroll through the items in the reverse order, hold the
Item button and press the ▲ button.
Menu
All of the items displayed by the control are organized
into five menus (View, Adjust, Time, Schedule, and Misc).
These menus are listed on the top left hand side of the
display (Menu Field). To select a menu, use the Menu
button. By pressing and releasing the Menu button, the
display sequences between the five menus. Once a menu
is selected, there will be a group of items that can be viewed
within the menu.
Item
The abbreviated name of the selected item will be displayed
in the item field of the display. To view the next available
item, press and release the Item button. Once you have
reached the last available item in a menu, pressing and
To make an adjustment to a setting in the control, begin by
selecting the ADJUST, TIME, SCHEDULE or MISC menu
using the Menu button. Then select the desired item using
the Item button. Finally, use the ▲, and / or ▼ button to make
the adjustment.
Additional information can be gained by observing the
Status field of the LCD. The status field will indicate
which of the control’s outputs are currently active. Most
symbols in the status field are only visible when the
VIEW menu is selected.
Page 3
Display
Menu Field
Displays the
current menu
Status Field
Displays the current
status of the
inputs, outputs and
control’s
operation
Buttons
Selects Menus, Items
and adjusts settings
Number Field
Displays the current value
of the selected item
MenuItem
Item Field
Displays the current
item selected
Symbol Description
PRIMARY PUMP
Displays when primary pump 1 or
primary pump 2 is in operation
BOILER
Displays which modulating output is
operating
LOCK
Displays when adjusting Access level if
Switch is set to lock.
WARNING
Displays when an error exists.
COMMUNICATION BUS
Displays when tN4 thermostats are
connected.
DHW PUMP
Displays when the DHW Pump is
operating
Schd Wake
UnOcc Sleep
Away
BOILER PUMP
Displays when the boiler pump 1, 2, 3,
or 4 are operating
COMBUSTION AIR DAMPER
Displays when the combustion air
damper relay is closed
SCHEDULE MASTER
Displays when the 275 is a schedule
master
WARM WEATHER SHUT DOWN
Displays when the control is in warm
weather shut down
MINIMUM & MAXIMUM
Displays when the boil target or the boil
supply is at a minimum or maximum
Displays the control operation as
indicated by the text
Page 4
Access Level
The access level restricts the number of Menus, Items,
and Adjustments that can be accessed by the user. The
Access Level setting is found in the Miscellaneous (MISC)
Menu. Select the appropriate access level for the people
who work with the control on a regular basis. There are
three Access Level Settings:
•
User (USER): Select this access level for building
supervisors and other non-technical staff to prevent
unauthorized access to installer and advanced level
Installer (INST): Select this access level to limit some of
•
the settings available to the installer. This is the factory
default access level.
Advanced (ADV): Select this access level to have complete
•
access to all of the control settings. In the display menu
tables, the appropriate access level needed to view each
item is shown in the Access column.
Note: the Lock / Unlock switch on the front of the control
must be set to unlock to change the access level.
settings.
Sequence of Operation
In order for the control to have a target water temperature there must be a demand. There are three different demands the
control can have: boiler demand, DHW demand, and setpoint demand.
Boiler Demand Section A
Once the control receives a boiler demand it calculates a
target water temperature based on the characterized heating
curve to provide outdoor reset for space heating. The control
can receive a boiler demand three different ways:
1. By applying 20-260 V (ac) to the boiler demand
terminals (27 & 28) when the DIP switch is set to
Demands.
2. From an Energy Management System (EMS) by
applying a 0-10 or 2-10 V (dc) signal to terminals 2 &
3 when the DIP switch is set to EMS.
3. From a tN4 device. This requires a tN4 thermostat to
be wired to terminals 1 & 2 so that the call for heat
can go over the communication bus.
20-260 V (ac)
2827
Boiler
Demand
Demand
23
OutCom
+
–
OROR
0-10 or
2-10 V (dc)
from EMS
21
tN4 Com
–
tN4
Demand
Outdoor Reset Section B
In a heating system, the rate of heat supplied to the building
must equal the rate at which heat is lost. If the two rates are
not equal, the building will either cool off or over heat.
The rate of building heat loss depends mostly on the outdoor
temperature. Outdoor Reset allows a hot water heating
system to increase the water temperature, adding heat to
the building, as the outdoor temperature drops. The rate
at which the water temperature is changed as a function
of outdoor temperature is defined by the characterized
heating curve.
Characterized Heating Curve
A characterized heating curve determines the amount the
target water temperature is raised for every 1° drop in outdoor
air temperature.
The characterized heating curve takes into account the
type of terminal unit that the system is using. Since different
types of heating terminal units transfer heat to a space using
different proportions of radiation, convection and conduction,
the supply water temperature must be controlled differently.
The control uses the terminal unit setting to vary the supply
water temperature to suit the terminal unit being used. This
improves the control of the air temperature in the building.
Boiler Characterized Heating Curve
Boiler
Design
Terminal
Unit
Outdoor
Design
Boiler
Indoor
Decreasing Outdoor Temperatures
Increasing Water Temperatures
Page 5
Terminal Unit Setting in Adjust Menu
Select the appropriate terminal unit in the adjust menu.
This will change the shape of the characterized heating
curve to better match the heat transfer properties of that
specific terminal unit.
Hydronic Radiant Floor (HRF1)
A heavy or high mass, hydronic radiant floor system. This
type of a hydronic radiant floor is embedded in either a thick
concrete or gypsum pour. This heating system has a large
thermal mass and is slow acting.
Hydronic Radiant Floor (HRF2)
A light or low mass, hydronic radiant floor system. Most
commonly, this type of radiant heating system is attached to
the bottom of a wood sub floor, suspended in the joist space,
or sandwiched between the subfloor and the surface. This
type of radiant system has a relatively low thermal mass
and responds faster than a high mass system.
Radiator (RAD)
A radiator terminal unit has a large heated surface that is
exposed to the room. A radiator provides heat to the room
through radiant heat transfer and natural convection.
Baseboard (BASE)
A baseboard terminal unit is similar to a radiator, but has
a low profile and is installed at the base of the wall. The
proportion of heat transferred by radiation from a baseboard
is greater than that from a fin-tube convector.
Boiler Terminal Unit Defaults
When a terminal unit is selected for boiler zones, the
control loads default values for the boiler design, boiler
maximum supply, and boiler minimum supply temperatures.
The factory defaults can be changed to better match the
installed system. Locate the Terminal Unit setting in the
Adjust menu.
Fancoil (COIL)
A fancoil terminal unit or air handling unit (AHU) consisting
of a hydronic heating coil and either a fan or blower. Air is
forced across the coil at a constant velocity by the fan or
blower and is then delivered into the building space.
Fin–tube Convector (CONV)
A convector terminal unit is made up of a heating element
with fins on it. This type of terminal unit relies on the natural
convection of air across the heating element to deliver
heated air into the space. The amount of natural convection
is dependant on the supply water temperature to the heating
element and the room air temperature.
Terminal Unit
High Mass Radiant
Low Mass Radiant
Fancoil
Fin-Tube Convector
Radiator
Baseboard
BOIL DSGNBOIL MAXBOIL MIN
120°F (49°C)140°F (60°C)OFF
140°F (60°C)160°F (71°C)OFF
190°F (88°C)210°F (99°C)140°F (60°C)
180°F (82°C)200°F (93°C)140°F (60°C)
160°F (71°C)180°F (82°C)140°F (60°C)
150°F (76°C)170°F (77°C)140°F (60°C)
Room Setting in Adjust Menu
The Room setting is the desired room air temperature,
according to the outdoor reset heating curve. The Room
setting parallel shifts the heating curve up or down to
change the target water temperature. Adjust the Room
setting to increase or decrease the amount of heat available
to the building. Once the heating curve has been set up
properly, the Room setting is the only setting that needs to
be adjusted. The default Room setting is 70°F (21°C), and
it can be adjusted for both the occupied and unoccupied
periods.
The outdoor design temperature is typically the coldest
outdoor air temperature of the year. This temperature is
used when doing the heat loss calculations for the building
and is used to size the heating system equipment. If a cold
outdoor design temperature is selected, the supply water
temperature rises gradually as the outdoor temperature
drops. If a warm outdoor design temperature is selected,
the supply water temperature rises rapidly as the outdoor
temperature drops.
Boiler Indoor Setting in Adjust Menu
The boiler indoor design temperature is the indoor
temperature the heating designer chose while calculating the
heat loss for the boiler water heated zones. This temperature
is typically 70°F (21.0°C). This setting establishes the
beginning of the boiler characterized heating curve.
Boiler Design Setting in Adjust Menu
The boiler design supply temperature is the boiler water
temperature required to heat the zones at the outdoor design
temperature, or on the typical coldest day of the year.
(Default automatically changes based on terminal unit
setting)
Warm Weather Shut Down (WWSD) Setting in Adjust
Menu
Warm Weather Shut Down disables the heating system when
the outdoor air temperature rises above this programmable
setting. When the control enters into WWSD, the LCD will
indicate this in the status field. WWSD is only available
when the DIP switch = Demands. The boilers will operate
when a Domestic Hot Water (DHW) demand or a Setpoint
Demand is present.
Boiler Operation Section C
The 275 is able to operate up to four modulating or on-off
boilers as a heat source. For proper operation of the boilers,
the 275 must be the only control that determines when a
boiler is to fire.
*Important note: The boiler operator, or aquastat, remains
in the burner circuit and acts as a secondary upper limit
on the boiler temperature. The boiler aquastat temperature
setting must be adjusted above the 275’s boiler maximum
setting in order to prevent short cycling of the burner.
Boiler Target Temperature
The boiler target temperature is determined by connected tN4
devices or by a Boiler, DHW or Setpoint demand received
by the control. An Energy Management System (EMS) can
also give a boiler target. The tN4 devices determine the
highest water temperature required and then request this
temperature on the tN4 boiler bus. The temperature request
creates a Boiler Demand and this is indicated on the display.
A DHW demand and a Setpoint demand have temperature
settings to which the boilers are operated to meet and are
able to override the tN4 bus temperature if required. The
control displays the temperature that it is currently trying to
maintain as the boiler supply temperature in the View menu.
If the control does not presently have a requirement for heat,
it does not show a boiler target temperature. Instead, “– – –”
is displayed in the LCD.
The boiler minimum is the lowest temperature that the
control is allowed to use as a boiler target temperature.
During mild conditions, if the control calculates a boiler
target temperature that is below the boiler minimum setting,
the boiler target temperature is adjusted to at least the
boiler minimum setting. The MIN segment is displayed in
the LCD while viewing the boiler supply or target and when
the boiler target is boiler minimum and the boiler supply is
less than boiler minimum plus 5°F (2.5°C). Set the Boiler
Minimum setting to the boiler manufacturer’s recommended
temperature.
Boil MIN + 5°F (2.5°C)
Boiler Differential
e
e
r
B
B
o
o
i
i
l
l
W
W
a
a
e
e
T
T
t
t
e
e
r
r
MIN segment on
r
u
u
t
t
a
a
r
r
e
e
p
p
m
m
Boil MIN
Boiler Maximum Setting in Adjust Menu
The boiler maximum is the highest temperature that the
control is allowed to use as a boiler target temperature.
The MAX segment is displayed in the LCD while viewing
the boiler supply or target and when the boiler target is
boiler maximum and the boiler supply is greater than boiler
maximum minus 5°F (2.5°C). Set the boiler maximum
setting below the boiler operator or aquastat temperature.
At no time does the control operate the boiler above 248°F
(120°C).
MAX
segment
on
B
B
o
o
i
i
l
l
W
W
a
a
e
e
T
T
t
t
r
r
e
e
r
r
e
e
p
p
m
m
e
e
r
r
u
u
t
t
a
a
MAX
segment
on
Boil MAX
Boil MAX – 5°F (2.5°C)
Boiler Differential
Page 7
Stage Delay Setting in Adjust Menu
The Stage Delay is the minimum time delay between the
firing of each stage. After this delay has expired the control
can fire the next stage if it is required. This setting can be
adjusted manually or set to an automatic setting. When the
automatic setting is used, the control determines the best
stage delay based on the operation of the system.
Boiler Relay Setting in Adjust Menu (per boiler)
The 275 provides a dry contact for either burner ignition or
boiler pump. Selection is made through the Boiler RELAY
setting in the adjust menu. Select ‘burner’ for boilers that
require a boiler enable signal as well as a modulating signal
The boiler differential can be fixed or automatically
determined by the control. The Auto Differential setting
balances the amount of temperature swing in the boiler
supply temperature with boiler on times, off times, and
cycle times. This reduces potential short cycling during
light load conditions.
Manual Differential
Differential = 10°F (6°C)
165°F (74°C)
160°F (71°C)
155°F (68°C)
Boiler
On
Boiler
On
Target + 1/2 Differential
Target
Target – 1/2 Differential
in order to operate. Select pump to operate a boiler pump
with post purge capabilities.
Automatic Differential
Boiler Mass Setting in Adjust Menu (per boiler)
Match the boiler mass setting with the thermal mass
characteristics of each boiler. The modulation of the boiler
Off
can become unstable if the incorrect Boiler Mass setting is
chosen. A key sign of unstable boiler modulation is that the
flame will continue to increase and then decrease in short
periods of time. By choosing a lower boiler mass setting,
Differential
On
the boiler response will become more stable.
LO
The LO setting is selected if the boiler that is used has
a low thermal mass. This means that the boiler has very
small water content and has very little metal in the heat
exchanger. A boiler that has a low thermal mass comes
up to temperature quite rapidly when fired. This is typical
of many copper fin-tube boilers.
The Lo mass setting provides a fast response to the heating
system.
MED
The MED setting is selected if the boiler that is used has
a medium thermal mass. This means that the boiler either
has a large water content and a low metal content or a
low water content and a high metal content. This is typical
Time
Rotation
The Rotate feature changes the firing order of the boilers
whenever one boiler accumulates 48 hours more run time
than any other boiler. Rotation will be forced if any boiler
accumulates 60 hours more run time. After each rotation,
the boiler with the least running hours is the first to fire and
the boiler with the most running hours is the last to fire.
This function ensures that all of the boilers receive equal
amounts of use. When the Rotate / Off DIP switch is set
to the Off position, the firing sequence always begins with
lowest boiler to the highest boiler.
Heating Load
of many modern residential cast iron boilers or steel tube
boilers.
The Med mass setting provides a moderate response to
12
21
the heating system.
HI
The HI setting is selected if the boiler that is used has a
high thermal mass. This means that the boiler has both
large water content and a large metal content. A boiler that
has a high thermal mass is relatively slow in coming up to
temperature. This is typical of many commercial cast iron
and steel tube boilers.
720 hours
To reset the rotation sequence (without regard to historical
running hours), toggle the Rotation DIP Switch Off for 3
seconds and on again. Note that the running hours (see
Run Time) in the View menu also need to be reset if you
want the rotation sequence and running hours display to
be synchronized.
672 hours
672 hours
720 hours
The Hi mass setting provides a slow response to the
heating system.
Boiler Differential Setting in Adjust Menu
A modulating boiler must be operated with a differential
while operating at Minimum Modulation. When the boiler
Boiler Run Time in View Menu
The running time of each boiler is logged in the view menu.
To reset the running time, select the appropriate Boiler Run
Time in the View menu and press and hold the Up and
Down buttons together until CLR is displayed.
is modulating above Minimum Modulation, the differential
does not apply. Instead, the modulation output signal is
determined using Proportional, Integral, and Derivative (PID)
logic in order to satisfy the boiler target temperature.
The 275 can operate up to four modulating boilers. The
control also provides dry contacts for either burner ignition
or boiler pump. Selection is made through Boiler Relay
setting in the Adjust menu.
Once a boiler is required to operate, the control outputs
an analog signal corresponding to the Start Modulation
setting and then turns on the boiler relay. Once the Fire
Delay time has elapsed, the modulating output is adjusted
to the Minimum Modulation setting. The control then holds
the modulating output at Minimum Modulation until the
Minimum Modulation Delay time has elapsed. Proportional,
Integral and Derivative (PID) logic is used in order to satisfy
the boiler target temperature.
Modulation Mode Setting in Adjust Menu
The control includes a Modulation Mode setting that
selects either Sequential or Parallel Modulation. Sequential
modulation should be used on boilers that are more efficient
when operating at high fire. Parallel modulation should be
used on boilers that are more efficient when operating at
low fire.
The 275 is restricted to sequential staging if:
1. 1 or more boilers are configured to be On/Off.
2. Condensing mode is selected.
3. The plant is configured for direct DHW.
Boiler Start Modulation Setting in Adjust Menu
(per boiler)
The Start Modulation setting is the lowest modulation
output required to obtain proper ignition. Whenever boiler
operation is required, the control outputs an analog signal
corresponding to the Start Modulation setting and closes
the boiler contact to turn on the burner. After the Fire Delay
has elapsed and the burner is ignited, the control modulates
the firing rate between the Minimum Modulation setting and
the Maximum Modulation setting.
40%40%40%40%
Sequential Modulation
In sequential modulation, the first boiler is turned on and
is modulated to satisfy light loads. Once the first boiler
does not have enough capacity to satisfy the load, the first
boiler reduces its modulation to provide a smooth transition
when the second boiler fires at low fire. The first boiler
then modulates up to maximum modulation as the load
increases. Only then is the second boiler able to increase
its output as the load continues to increase. When the third
boiler is required, the second boiler reduces its modulation
to allow the third boiler to operate at low fire. As the load
continues to increase, the second boiler is modulated to
its maximum and then the third boiler is modulated. The
operation is reversed when shutting off the boilers.
100%60%OffOff
Parallel Modulation
In parallel modulation, the first boiler turns on at low fire
and begins to increase its modulation. Once the first boiler’s
output is greater than the combined output of the first and
second boiler’s low fire, the first boiler is modulated down
to low fire and the second boiler is fired at low fire. The
two boilers now modulate together. Once the two boiler’s
combined output is greater than the combined output of
all three boilers operating at low fire, the first and second
boilers are modulated down to low fire, and all three boilers
are operated at low fire. The boilers are then modulated
as the load increases. The operation is reversed when
shutting off the boilers.
Boiler Fire Delay Setting in Adjust Menu
(per boiler)
The Boiler Fire Delay sets the time it takes for the boiler to
generate flame from the time the boiler turns on.
Boiler Contact Closed
Fire Delay
Burner On
Time
Boiler Motor Speed Setting in Adjust Menu
(per boiler)
The Motor Speed is the amount of time the boiler requires
to go from 0% modulation to 100% modulation.
Gas valve actuating motors have a design time from
fully closed to fully opened which can be found in the
manufacturer’s manual. The Motor Speed should be set
to this time.
The Motor Speed setting for a Variable Frequency Drive
(VFD) is the amount of time required to go from a stopped
position to 100% fan speed. Since a VFD has a very quick
response rate, it may be necessary to increase the Motor
Speed setting in order to increase the stability of the boiler
modulation.
OR
Boiler % Modulation in View Menu
View the current % modulation of each boiler in the View
menu.
The Minimum Modulation setting is the lowest modulation
output to obtain low fire. The Minimum Modulation setting
is typically based on the turndown ratio of the boiler. The
control adjusts the modulating output signal from Minimum
Modulation to 0% after the burner turns off and boiler
operation is not required.
To calculate the Minimum Modulation, use the following
formula:
For 0 to 10 V (dc):
Minimum
Modulation
0 V (dc) –
=
Boiler’s Minimum
Input Signal
0 – 10 V (dc)
x 100%
Example:
A boiler requires a 1.8 V (dc) signal to fire the boiler at
low fire. The boiler can be modulated to 10 V (dc) where it
reaches high fire. This means the boiler’s input signal range
is 1.8 to 10 V (dc). The 275 control has an output signal
range of 0 to 10 V (dc).
To make the two signal ranges the same, the Minimum
Modulation required is:
The Minimum Modulation Delay is the time that the boiler
burner must hold the modulation of the boiler at a minimum
before allowing it to modulate any further.
Boiler Maximum Modulation Setting in Adjust Menu
(per boiler)
The Maximum Modulation defines the maximum output
signal from the control to the boiler burner. It is based on
a percentage of the control’s output signal range. The
maximum modulation setting for boilers with power burners
is typically set to 100%.
For boilers with electronic operators, the boiler’s input signal
range may not match the output signal range of the 275
control. The Maximum Modulation setting limits the control
output range in order to match the boiler’s input range.
To calculate the Maximum Modulation, use the following
formula:
For 0 to 10 V (dc):
Maximum
Modulation
0 V (dc) –
=
Boiler’s Maximum
Input Signal
0 – 10 V (dc)
x 100%
Example:
A boiler’s input signal range is 0 to 9 V (dc). The 275
control has an output signal range of 0 to 10 V (dc). To
make the two signal ranges the same, the Maximum
Modulation required is:
Maximum Modulation = (0 – 9) ÷ (0 – 10) x 100% = 90%
10 V (dc)
Maximum
Modulation
Control’s
Output
Signal
Range
100%
88%
0%
9 V (dc)
Boiler’s
Input
Signal
Range
0 V (dc)0 V (dc)
Boiler’s
Maximum
Input
Signal
Minimum and Maximum Boiler Outputs (MBH)
Setting in Adjust Menu
(per boiler)
In order to accommodate different boiler capacities in the
same system, a minimum and maximum boiler output
for each boiler can be set. This allows the control to
properly operate the boilers using either sequential or
parallel modulation. Each boiler typically has a rating plate
that specifies the minimum and maximum output. This
information is also available in the boiler manual.
The minimum and maximum boiler output is expressed
in MBH. 1 MBH = 1,000 BTU / hour. The range is from 1
MBH to 1,999 MBH.
For example, if a boiler has a maximum output of 100,000
BTU / hr and a minimum output of 20,000 BTU / hr (turn
down ratio of 5):
The 275 can operate up to four modulating or on/off boilers
in any combination. Each boiler stage has a Boiler Mode
setting in the the Adjust menu that allows the selection of
either modulating (Mod) or on/off (OnOF). By selecting a
boiler stage to on/off, the 275 then uses sequential boiler
staging, the stage relay is set to operate a burner, and
settings related to modulation are removed from the boiler
settings.
OEM Boilers Equipped With A BTC I Control Section F
The 275 can sequence up to four boilers equipped with an
integral BTC I control. Boilers that include the BTC I control
may have multi-stage or modulating burners. Each boiler
is connected to the 275 using two wires connected to the
Mod + and - wiring terminals for each boiler stage. The 275
also allows combinations of multi-stage boilers together with
modulating boilers. In total, the 275 is able to control up to
16 stages. For information on BTC I equipped boilers and
how to installed with the 275, please see tekmar Service
Bulletin SB 055.
Fixed Lead and Fixed Last Section G
Fixed Last
In some applications, it may be desirable to have the last
boiler fire last at all times while the firing sequence of
the remaining boilers is changed using Equal Run Time
Rotation. This configuration is typical of installations where
the boiler plant includes higher efficient boilers and a single
lesser efficient boiler. The lesser efficient boiler is only
desired to be operated when all other boilers in the plant are
on and the load cannot be satisfied. This rotation option is
selected by setting the Fixed Last / Off DIP switch to Fixed
Last. With a fixed last rotation, the last boiler is the last to
stage on and the first to stage off. The Fixed Last is always
applied to the boiler 4 output.
Fixed Lead & First On / First Off
In some applications, it may be desirable to have the first
boiler fire first at all times while the firing sequence of
the remaining boilers is changed using Equal Run Time
Rotation. This rotation option is selected by setting the Fixed
Lead / Off DIP switch to the Fixed Lead position. The Fixed
Lead is always applied to the boiler 1 output.
When using the Fixed Lead rotation option, a selection must
be made between First On / Last Off and First On / First
Off using the DIP switch.
When First On / First Off is selected, the lead boiler is always
staged on first and staged off first. This configuration is
typical of installations where the boiler plant includes similar
boilers but the first boiler is required to be the first to fire in
order to establish sufficient draft for venting.
Fixed Lead & First On / Last Off
When First On / Last Off is selected, the lead boiler is
always staged on first and staged off last. This configuration
is typical of installations where the boiler plant includes a
single higher efficient boiler with lesser efficient boilers.
The lead boiler is the high efficiency boiler, therefore it the
last boiler to be sequenced off.
Condensing and Non-Condensing Boiler Groups Section H
Operating a boiler plant that contains both condensing
(high initial cost) and non-condensing (lower intial cost)
boilers allows the boiler plant to achieve nearly the same
operating efficiencies as operating all condensing boilers
but at a much lower installed cost to the building owner.
High system efficiency can be acheived as long as the
condensing boilers are the first to operate in the firing
sequence. During mild weather, the lead condensing boilers
operate at lower boiler temperatures and achieve their peak
boiler effiencies while the non-condensing boilers are rarely
operated. During very cold weather, the boiler target is often
above the boiler’s condensation point and the condensing
and non-condensing boilers operate together at roughly
the same efficiency level.
The 275 supports the operation of condensing and noncondensing boilers as separate groups through either the
Fixed Lead or Fixed Last options. When a condensing
boiler is operating, it is desirable to operate the boilers
without a boiler minimum temperature being applied to the
boiler target. This allows the condensing boiler to operate
at its maximum efficiency. When a non-condensing boiler
is operating, a boiler minimum temperature should be
applied to the boiler target to prevent damage to the noncondensing boiler heat exchanger from sustained flue gas
condensation.
To operate one to three condensing boilers as the lead
boiler group, and operate a single non-condensing boiler
as the lag boiler, set the Fixed Last / Off DIP switch to the
Fixed Last position and select the Condensing Lead (COND
LEAD) setting to on. The boilers within the condensing lead
group can be operated using Equal Run Time Rotation to
balance running hours.
To operate a single condensing boiler as the lead boiler,
and operate one to three non-condensing boilers as the lag
group, set the Fixed Lead / Off DIP switch to the Fixed Lead
position and select the Condensing Lead (COND LEAD)
setting to on. The boilers within the non-condensing lag
group can be operated using Equal Run Time Rotation to
balance running hours.
In the event that Fixed Lead or Fixed Last is selected and
all boiler are non-condensing, select the Condensing Lead
(COND LEAD) setting to off.
Page 11
Domestic Hot Water Operation Section I
DHW operation is only available when the Pump Sequencer
DIP Switch is set to Off.
DHW Demand
DHW Demands come from one of three sources: an external
aquastat, a DHW tank sensor, or a tN4 Setpoint Control.
Once the control detects a DHW Demand, the DHW
Demand segment is displayed in the LCD. If an External
Powered DHW Demand is applied while the DHW sensor
is enabled in the 275, an error message is generated and
both demands are ignored.
A DHW demand from a tN4 Setpoint Control can coexist with
another DHW demand without generating an error message.
The 275 will then use the higher of the two targets.
Powered DHW Demand
The control registers a DHW Demand when a voltage
between 20 and 260 V (ac) is applied across the DHW
Demand terminals 29 and 30. An aquastat or setpoint
control is used to switch the DHW Demand circuit. Program
a DHW Exchange temperature for the Occupied and
UnOccupied events in the Adjust Menu.
• DHW Sensor must be set to Off.
DHW Sensor
The control can register a DHW Demand when A DHW
Sensor is wired to terminals 5 and 6. Once the DHW Sensor
drops 1/2 of the DHW Differential setting below the DHW
Setpoint, the control registers a DHW Demand. Program a
DHW Tank temperature for the Occupied and UnOccupied
events in the Adjust Menu.
The DHW Sensor must be set to On. There cannot be
•
an externally powered DHW demand when using a
DHW sensor.
tN4 Setpoint Control in DHW Mode
The control can register a DHW Demand when a tN4
Setpoint Control in DHW Mode is wired to terminals 1 and 2.
The DHW Demand is sent over the tN4 communication bus
when the Setpoint Control calls for heat. Program a DHW
tank temperature for the Occupied and UnOccupied events
and the desired supply water temperature required on the
tN4 bus in the Adjust Menu of the tN4 Setpoint Control.
DHW Differential Setting in Adjust Menu
Due to large differences between the heating load and the
DHW load, a separate DHW differential should be used
whenever a DHW Demand is present. This will improve
staging and boiler cycling. When using a DHW Sensor, a
DHW Demand is registered when the DHW sensor drops 1/2
of the DHW Differential setting below the DHW setting. The
DHW Demand is satisfied once the DHW Sensor rises 1/2
of the DHW Differential setting above the DHW setting.
OFF
Boiler Target Temperature during a DHW Demand
If a Powered DHW Demand is present, the boilers are
operated to maintain the DHW Exchange temperature. If a
DHW sensor demand is present, the boilers are operated
to maintain a temperature of 40°F (22°C) above the DHW
tank temperature. If a tN4 demand is present, the primary
pump is turned on according to the device’s reported
requirements and the boilers are operated to maintain the
devices requested target on the bus. The DHW Demand
overrides the boiler reset target temperature, except when
the boiler reset target is higher than the DHW target.
Regardless of DHW settings and requested targets, the
boilers will maintain a target temperature no higher than
the Boil MAX setting.
DHW During UnOccupied
When using a Powered DHW Demand, the control has a
DHW Exchange UnOccupied setting that allows the installer
to select On or Off. When set to On, and the control receives
a DHW Demand during an UnOccupied or Sleep period,
the control continues operation of the DHW system as it
would during the Occupied and Wake periods. When set to
Off, the control will ignore a DHW Demand for the duration
of the UnOccupied and Sleep periods.
When using a DHW Sensor, a second DHW temperature
setting is available for the UnOccupied or Sleep period.
DIP Switch must be set to Setback to view UnOccupied
items.
During the Away Scene, DHW demands are ignored.
DHW Mode Setting in the Adjust Menu
The control has six different DHW Modes that affect pump
operation. The required DHW Mode setting will depend on
the piping arrangement of the DHW tank and whether or
not priority for DHW is necessary. DHW Priority stops or
limits the delivery of heat to the building heating system
while the DHW tank calls for heat. This allows for quick
recovery of the DHW tank.
Mode OFF / No DHW Generation
All DHW demands are ignored. If this mode is selected
while DHW generation is underway, all DHW operation
ceases.
When a valid DHW Demand is present, the DHW relay
(terminal 23) turns on. The primary pump can operate
when a Boiler Demand is present. It is assumed that the
DHW pump will provide adequate flow through the heat
exchanger and the boiler. Heating zones are unaffected
by DHW operation.
Mode 4 - DHW in Primary/Secondary with Priority
When a valid DHW Demand is present, the DHW relay
(terminal 23) and Primary Pump relay (terminal 24) turn
on. If the boilers are unable to maintain the boiler target
temperature, space heating zones are shut off sequentially
using tN4 communication in order to provide priority to the
DHW tank. For non-tN4 systems, priority requires the use
of an external relay to force the heating zones off.
Mode = 1
DHW
Pump
Primary
Pump
Mode 2 - DHW in Parallel with Priority
When a valid DHW Demand is present, the DHW relay
(terminal 23) turns on. The primary pump can operate
when a Boiler Demand is present. If the boilers are unable
to maintain the boiler target temperature, space heating
zones are shut off sequentially using tN4 communication
in order to provide priority to the DHW tank. For non-tN4
systems, the primary pump shuts off to provide priority. It
is assumed that the DHW pump will provide adequate flow
through the heat exchanger and the boiler.
Mode = 2
OFF
DHW
Pump
Primary
Pump
Mode = 4
DHW
Pump
Primary
Pump
OFF
Mode 5 - DHW in Parallel / Last Boiler with Priority
When a valid DHW Demand is present, the DHW relay
(terminal 23) turns on and boiler pump 4 turns off. The
control uses the DHW Exchange Supply Sensor in order
to measure the boiler supply temperature supplied to the
indirect tank. There are two boiler target temperatures, one
for the heating system (BOIL TARGET) and one for the
indirect DHW system (BOIL DHW TARGET). In this mode,
the DHW Demand can only be provided from an External
Powered Demand or tN4 Setpoint Control in DHW mode.
All boilers are used for space heating requirements
•
Boiler 4 is used for DHW when there is a DHW demand
•
The dedicated DHW boiler is always boiler 4 (relay 4),
•
even if there are less than 4 boilers.
If boiler 4 is disabled and mode 5 is selected then the
•
dedicated DHW boiler (boiler 4) will not operate.
DHW Exchange
Supply Sensor
Mode = 5
Mode 3 - DHW in Primary/Secondary with No Priority
When a valid DHW Demand is present, the DHW relay
(terminal 23) and Primary Pump relay (terminal 24) turn
on. Heating zones are unaffected by DHW operation. This
mode can be used if the DHW tank is piped in parallel and
a DHW valve is installed (need to use an external relay to
power the valve with 24 V (ac) since the DHW pump output
is a 120 V (ac) powered output).
When a valid DHW Demand is present from the DHW
Sensor, the primary pump relay turns on. The DHW Relay
in this mode is used as the DHW recirculation pump and
operates continuously in the Occupied period and cycles
with the primary pump in the UnOccupied period. The boiler
plant is sequenced based only on the DHW Sensor.
All boilers are used for DHW requirements
•
Requires DHW demand from DHW sensor
•
DHW Pump Relay is used for DHW recirculation pump
•
Boiler Supply Sensor Not Required
•
DHW Post Purge
After the DHW Demand is removed, the control performs
a purge. The control shuts off the boilers and continues to
operate the DHW Pump and the primary pump if applicable.
This purges the residual heat from the boilers into the
DHW tank. The control continues this purge until one of
the following occurs:
1. A Boiler Demand is detected
2. The boiler supply drops 20°F (11°C) below the DHW
target temperature
3. The DHW tank temperature rises above the DHW
setpoint plus 1/2 DHW Differential
On/
Off
Mode = 6
On/
Off
4. Two minutes elapse
DHW Mixing Purge
After DHW operation, the boiler is extremely hot. At the same
time, the heating zones may have cooled off considerably
DHW Sensor
after being off for a period of time. When restarting the
heating system after a DHW demand with priority, the
Recirculation
Pump
control shuts off the boiler and continues to operate the
DHW pump while the primary pump is turned on. This allows
some of the DHW return water to mix with the cool return
DHW Priority Override Setting in Adjust Menu
DHW Priority Override applies to DHW MODE 2 and 4, as
well as Mode 5 if there is a tN4 device with DHW. It prevents
the building from cooling off too much or the possibility of
a potential freeze up during DHW priority.
When set to auto, the priority time is calculated based
on outdoor temperature. At or below the design outdoor
temperature, 15 minutes are allowed for DHW priority.
At or above 70°F (21°C), 2 hours are allowed for DHW
priority. The time allowed for DHW priority varies linearly
between the above two points. There is a manual setting
also available in the adjust menu.
The priority timer does not start timing until priority is selected
and both a DHW Demand and a Boiler Demand exist together.
Once the allowed time for priority has elapsed, the control
overrides the DHW priority and resumes space heating.
Automatic Priority Override
2 hours
water from the zones and temper the boiler return water.
DHW with Low Temperature Boilers
If DHW heating is to be incorporated into a low temperature
system such as a radiant floor heating system, a mixing
device is often installed to isolate the high DHW supply
temperature from the lower system temperature. If a mixing
device is not installed, high temperature water could be
supplied to the low temperature system while trying to
satisfy the DHW demand. This may result in damage to
the low temperature heating system.
The control is capable of providing DHW heating in such a
system while minimizing the chance that the temperature
in the heating system exceeds the design supply water
temperature. In order to do this, the following must be true:
tN4 Present
•
DHW MODE 2 or 4
•
Boil MIN OFF
•
On a call for DHW, the control provides DHW priority by
sending a message on the boiler temperature bus to the tN4
thermostats to shut off the heating zones for a period of time.
The length of time is based on the outdoor air temperature as
described in the DHW Priority Override section. However, if
the DHW Demand is not satisfied within the allotted time, the
boiler shuts off and the heat of the boiler is purged into the
15 mins
DHW tank. A DHW mixing purge occurs in order to reduce
the boiler water temperature and once the boiler supply
70°F (21°C)
Design Temperature
Conditional DHW Priority
If the boiler supply temperature is maintained at or above
the required temperature during DHW generation, this
temperature is sufficiently reduced, the DHW Pump contact
shuts off. The heating system zones are allowed to turn on for
a period of time to prevent the building from cooling off. After
a period of heating, and if the DHW Demand is still present,
the control shuts off the heating system and provides heat
to the DHW tank once again.
indicates that the boilers have enough capacity for DHW
and possibly heating as well. As long as the boiler supply
temperature is maintained near the target, DHW and heating
DHW Boilers Setting in Adjust Menu
Select the number of boilers to use for DHW generation.
Setpoint operation is only available when DHW Mode is
set to Off.
The control can operate to satisfy the requirements of a
setpoint load in addition to a space heating load. A setpoint
load overrides the current outdoor reset temperature in
order to provide heat to the setpoint load.
Setpoint Demand
Setpoint Demands come from one of two sources: a
Powered Setpoint Demand, or a tN4 Setpoint Control.
Powered Setpoint Demand
The control registers a Setpoint Demand when a voltage
between 20 and 260 V (ac) is applied across the Setpoint
Demand terminals 29 and 30. An aquastat or setpoint
control is used to switch the Setpoint Demand circuit.
Program a Setpoint target for the Occupied and UnOccupied
events in the Adjust Menu.
• DHW Mode must be set to Off.
tN4 Setpoint Control
The control can register a Setpoint Demand when a tN4
Setpoint Control is wired to terminals 1 and 2. The Setpoint
Demand is sent over the tN4 communication bus when
the Setpoint Control calls for heat. Program a Setpoint
temperature for the Occupied and UnOccupied events and
the desired supply water temperature required on the tN4
bus in the Adjust Menu of the tN4 Setpoint Control.
• DHW Mode must be set to Off.
A demand from a tN4 Setpoint Control can coexist with another
setpoint demand without generating an error message. The
275 will then use the higher of the two targets.
DIP Switch must be set to Setback to view UnOccupied
items.
During the Away Scene, Setpoint demands are ignored.
Setpoint Mode Setting in the Adjust Menu
The control has four different Setpoint Modes that affect
pump operation. The required Setpoint Mode setting will
depend on the piping arrangement and whether or not
priority is necessary. Setpoint Priority stops or limits the
delivery of heat to the building heating system while the
Setpoint load calls for heat. This allows for quick recovery
of the Setpoint load.
Mode OFF - No Setpoint Operation
All Setpoint demands are ignored. If this mode is selected
while Setpoint operation is underway, all Setpoint operation
ceases.
Mode 1 - Setpoint in Parallel with No Priority
Whenever a Setpoint Demand is present, the boilers are
operated to maintain the setpoint target. The primary
pump does not turn on, but may operate based on a Boiler
Demand. It is assumed that the Setpoint pump will provide
adequate flow through the heat exchanger and the boiler.
Mode = 1
Setpoint
Primary
Pump
Boiler Target Temperature during a Setpoint Demand
If a Powered Setpoint Demand is present, the boilers are
operated to maintain the Setpoint target. If a tN4 demand
is present, the primary pump is turned on according to
the device’s reported requirements and the boilers are
operated to maintain the devices requested target on the
bus. The Setpoint Demand overrides the boiler reset target
temperature, except when the boiler reset target is higher
than the Setpoint target. Regardless of Setpoint settings
and requested targets, the boilers will maintain a target
temperature no higher than the Boil MAX setting.
Setpoint During UnOccupied
When using a Powered Setpoint Demand, the control has
a Setpoint UnOccupied setting that allows the installer to
select On or Off. When set to On, and the control receives
a Setpoint Demand during an UnOccupied or Sleep period,
the control continues operation of the Setpoint system as
it would during the Occupied and Wake periods. When set
to Off, the control will ignore a Setpoint Demand for the
duration of the UnOccupied and Sleep periods.
Mode 2 - Setpoint in Parallel with Priority
When a Setpoint Demand is present, the boilers are
operated to maintain the setpoint target. The primary
pump can operate when a Boiler Demand is present. If the
boilers are unable to maintain the boiler target temperature,
space heating zones are shut off sequentially using tN4
communication in order to provide priority to the Setpoint
Load. For non-tN4 systems, the primary pump shuts off to
provide priority. It is assumed that the Setpoint pump will
provide adequate flow through the heat exchanger and
the boiler.
Mode 3 - Setpoint in Primary/Secondary with No Priority
Whenever a Setpoint Demand is present, the primary pump
is turned on and the boilers are operated to maintain the
setpoint target.
Mode = 3
Setpoint
Automatic Priority Override
2 hours
15 mins
Primary
Pump
Mode 4 - Setpoint in Primary/Secondary with Priority
Whenever a Setpoint Demand is present, the primary pump
is turned on and the boilers are operated to maintain the
setpoint target. Space heating zones will be shut off if the
boilers are unable to maintain the boiler target temperature
using tN4 communication. For non-tN4 systems, an external
relay is required to force off the heating zones.
Mode = 4
Setpoint
OFF
Primary
Pump
Setpoint Priority Override Setting in Adjust Menu
Setpoint Priority Override applies to SETPOINT MODE 2 and
MODE 4. To prevent the building from cooling off too much or
the possibility of a potential freeze up during setpoint priority,
the control limits the amount of time for setpoint priority.
When set to auto, the priority time is calculated based
on outdoor temperature. At or below the design outdoor
temperature, 15 minutes are allowed for Setpoint priority. At or
above 70°F (21°C), 2 hours are allowed for Setpoint priority.
The time allowed for Setpoint priority varies linearly
between the above two points. There is a manual setting
also available in the adjust menu.
The priority timer does not start timing until priority is
selected and both a Setpoint Demand and a Boiler Demand
exist together. Once the allowed time for priority has
elapsed, the control overrides the Setpoint priority and
resumes space heating.
Design Temperature70°F (21°C)
Conditional DHW Priority
If the boiler supply temperature is maintained at or above
the required temperature during setpoint generation, this
indicates that the boiler has enough capacity for setpoint
and possibly heating as well. As long as the boiler target
temperature is maintained, setpoint and heating occur at
the same time.
Setpoint Post Purge
After a tN4 Setpoint Demand is removed, the control
performs a purge. The control shuts off the boilers and
continues to operate the Setpoint Pump and the primary
pump if applicable. This purges the residual heat from the
boilers into the Setpoint load. The control continues this
purge until one of the following occurs:
1. A Boiler Demand is detected
2. The boiler supply drops 20°F (11°C) below the Setpoint
target temperature
The control can accept an external DC signal from an Energy
Management System (EMS) in place of the outdoor sensor.
The control converts the DC signal into the appropriate
boiler target temperature between 50°F (10°C) and 210°F
(99°C) based on the EMS Input Signal and Offset settings.
To use the external input signal, the EMS / Demands DIP
switch must be set to EMS.
An external signal is generated by applying a voltage
between 0 V (dc) and 10 V (dc) across the Out + and Com
– terminals (3 and 2). Voltages that exceed 10 V (dc) will
still be considered a 10 V (dc) signal.
Once voltage is applied, the EMS Input Signal pointer is
displayed in the LCD and the control calculates a boiler
target and closes the primary pump contact. The control
then modulates the boiler(s), if required, to maintain the
target supply temperature.
If the EMS signal goes below the minimum voltage, the
EMS Input Signal pointer is turned off in the display. The
boiler target temperature is displayed as “– – –” to indicate
that there is no longer a call for heating.
Input Signal
The control can accept either a 0 - 10 V (dc) signal or a
2 - 10 V (dc) signal. The External Input Signal setting must
be set to the proper setting based on the signal that is being
sent to the control.
0 - 10 V (dc) or 0 - 20 mA
When the 0 - 10 V (dc) signal is selected, an input voltage
of 1 V (dc) corresponds to a boiler target temperature of
50°F (10°C). An input voltage of 10 V (dc) corresponds
to a boiler target temperature of 210°F (99°C). As the
voltage varies between 1 V (dc) and 10 V (dc) the boiler
target temperature varies linearly between 50°F (10°C) and
210°F (99°C). If a voltage below 0.5 V (dc) is received the
boiler target temperature is displayed as “– – –” indicating
that there is no longer a call for heating.
A 0 - 20 mA signal can be converted to a 0 - 10 V (dc) signal
by installing a 500 resistor between the Out + and Com
– terminals (3 and 2).
2 - 10 V (dc) or 4 - 20 mA
When the 2 - 10 V (dc) signal is selected, an input voltage
of 2 V (dc) corresponds to a boiler target temperature of
50°F (10°C). An input voltage of 10 V (dc) corresponds
to a boiler target temperature of 210°F (99°C). As the
voltage varies between 2 V (dc) and 10 V (dc) the boiler
target temperature varies linearly between 50°F (10°C) and
210°F (99°C). If a voltage below 1.5 V (dc) is received the
boiler target temperature is displayed as “– – –” indicating
that there is no longer a call for heating.
A 4 - 20 mA signal can be converted to a 2 - 10 V (dc) signal
by installing a 500 resistor between the Out + and Com
– terminals (3 and 2).
For external input operation, the boiler target (determined
from the external input signal) may be fine tuned. The
Offset setting is used to provide the fine tuning. The Offset
setting may be adjusted ±10°F. When set to 0°F, if the
temperature determined from the external signal is 140°F,
the boiler target will be 140°F. When set to +5°F and with
the same external signal represents 140°F, the boiler target
will be 145°F.
Example
Range = 0 - 10 V (dc)
Input = 7 V (dc) 157°F (69°C)
Offset = +5°F (3°C) + 5°F (3°C)
Boiler Target = 162°F (72°C)
The minimum and maximum settings also apply for external
input operation. For example, if a boiler minimum of 140°F
is set and the external signal received represents 80°F, the
boiler target will be 140°F. The MIN segment will also be
displayed to indicate that a limiting condition is in effect.
This also applies for the MAX segment limit.
Whenever an external signal is used, the control can still
provide all DHW OR Setpoint functions.
Page 17
Pump Operation Section L
Primary Pump Operation
The control includes two primary pump outputs with
capability for sequencing. Primary pump sequencing is
activated through a DIP switch. Only primary pump 1
is operated when pump sequencing is turned off, while
primary pumps 1 and 2 are operated in stand-by mode
when pump sequencing is turned on.
The running times of the primary pumps are logged in the
view menu. To reset these values back to zero, press and
hold the up and down button while viewing this item.
Note: Once primary pump sequencing is selected, DHW
operation is not available. Setpoint operation, however, is
available if primary pump sequencing is selected.
The primary pump(s) will operate when the control receives
an appropriate demand:
External Boiler Demand
•
tN4 Boiler Demand and that zone’s thermostat has H1
•
Pump set to On.
DHW Demand and the control is set to DHW Mode 3,
•
4, or 6.
Setpoint Demand and the control is set to Setpoint Mode
•
3 or 4.
The primary pump also operates when the control is
completing a DHW Purge.
tN4 thermostats can select whether the primary pump is
required to operate or not. tN4 thermostats also include a
thermal actuator setting which can delay the primary pump
for 3 minutes to allow thermal actuators to open.
Stand-by Operation
The control only operates one primary pump at a time. A
flow proof device can be used to detect when stand-by
pump operation is required.
When a demand is registered, the lead pump is activated,
•
and the control waits for flow to be established within the
flow proof delay time.
If no flow is established, the lead pump is de-activated,
•
the lag pump is activated and the control waits again for
the flow to establish within the flow proof delay time.
If again no flow is established, the lag pump is de-activated
•
and the control stops operation until the error is cleared.
Verify that the pumps and flow proof device are working
correctly before clearing the error.
If the lead pump establishes flow, and fails during
•
operation, the lag pump is activated.
If at any time, one or both pumps fail to prove flow, an
•
error message is displayed.
Normal Operation
275
On
Flow Proof
Device
Off
Flow Proof
The control includes a flow proof demand in order to prove
flow once a primary pump has turned on. In order for
boiler operation to commence, the proof demand must be
present. A flow proof signal is required at all times during
pump operation. A flow proof is generated by applying a
voltage between 20 and 260 V (ac) across the Flow Proof
terminals (30 and 31). Once voltage is applied, the Proof
Demand indicator is turned on in the LCD.
Once a pump contact is turned on, a flow proof signal must
be present before the flow proof delay has expired.
The flow proof demand is selected by setting the Proof
Demand item in the Adjust menu to F P (flow proof).
A flow proof demand can come from a flow switch, pressure
differential switch, current sensing or power sensing device.
∆PPressure Differential Switch
3130
Pr.Com
DemDem
N
FSFlow Switch
KWPower Sensing Device
L
20 to 260 V (ac)
Amp Current Sensing Device
Stand-by Pump Operation
275
Optional
Failed
On
Alert
Flow Proof
Device
Flow Proof Delay Setting in Adjust Menu
The control waits a period of time to receive a flow proof
demand from the time the primary pump turns on. If the
control does not receive a flow proof demand within that
period of time, the primary pump turns off and the stand-by
primary pump (if active) turns on. The control then waits
that period of time again for the stand-by primary pump to
prove flow. If flow is not proven, the stand-by pump turns
off. The period of time is set through the Proof Demand
‘Pump’ DLY item in the Adjust menu and it is adjustable
between 10 seconds and 3 minutes.
The control includes a flow proof demand test in order to
determine if the flow/pressure device has failed. A flow
proof failure is detected if a flow proof is present after the
pumps have been shut off for more than four minutes. This
can occur if the flow proof device sticks in the on position
even when flow has stopped in the system. A proof demand
error will latch when this condition exists.
Primary Pump Rotation Setting in Adjust Menu
The control rotates the pumps based on the Rotate item
in the Adjust menu. Frequency of Rotation is based on the
running time of the pumps. Rotation is done when the lead
pump is off. If the lead pump runs continuously, the rotation
is delayed for up to 12 hours. If the pump runs continuously
and rotation is required, the control shuts off the lead pump
and 1 second later the stand-by pump is turned on. This
eliminates overloading the pump electrical circuit. Upon
turning on the stand-by pump the flow proof input is checked
after the flow proof demand delay time.
Primary Pump Purge
After the last valid demand is removed, the primary pump
is operated for an additional purging time of at least 20
seconds. If the last demand came from a tN4 zone, the
control sends out a purge message to override the zone
open for the duration of the boiler purge. At the end of
the purge, the zone override is removed so the zone is
allowed to close and turn off the primary pump. If the last
demand came from a non-tN4 zone, the purge period for
the primary pump is adjustable between 10 seconds and
19:55 minutes.
Boiler Pump Operation
The control is capable of operating individual boiler pumps.
This feature is available by setting the Boiler relays to pump
in the Adjust Menu.
The control includes a boiler pump pre-purge which operates
the respective boiler pump for a period of time before the
boiler is ignited in order to purge potential residual heat out
of the boiler. The pre-purge time is determined from the
boiler mass setting. As the boiler mass setting is increased,
the boiler pump pre-purge time is also increased. The
pre-purge time is fixed at 4 seconds whenever a DHW /
Setpoint demand is provided in order to reduce boiler pickup times.
The control includes a boiler pump post-purge feature that
operates the respective boiler pump for a period of time
after the boiler is turned off. This feature will purge heat out
of the boiler and aid in reducing “kettling”. The amount of
time for the boiler pump post purge is adjustable between
10 seconds and 19:55 minutes. See the boiler pump purge
setting in the adjust menu.
Combustion Air and Alert Settings Section M
Relay Setting in Adjust Menu (C.A. / Alert)
The control includes an auxiliary relay that can be used
either for a combustion / venting device or an Alert. Selection
is made through the Relay item in the Adjust menu.
Alert
When the Relay is set to Alert, terminals 21 and 22 close
whenever a control or sensor error is detected, or when a
warning or limiting condition is detected. When the alert
contact closes, refer to the Error Messages section of this
brochure to determine the cause of the alert and how to
clear the error.
Boiler Alarm
For the Boiler Alarm item to appear in the Adjust menu,
the Relay must be set to Alert. If no temperature increase
is detected at the boiler supply sensor within this delay
period, the Alert relay will close and the control will display
the Boiler Alarm error message. To clear the error, press
and hold the up and down buttons together for 5 seconds
while viewing the error message in the View menu.
Combustion Air (C.A.)
When the Relay is set to C.A., terminals 21 and 22 operate
a combustion air damper / fan motor or power vent motor.
The Relay closes once a demand is received and the
control has determined that one or more boilers need to
be turned on.
Combustion Air Proof Demand Setting in Adjust Menu
The proof demand can be used to prove a combustion air
or venting device if set to C.A. Boiler operation cannot occur
until the proof demand is present. If the proof demand is
lost during operation, the boiler plant is sequenced off.
Combustion Air Proof Demand Delay Setting in
Adjust Menu
The control includes a time delay that is associated with
the proof demand feature in order to determine if the proof
device is functional. Once the C.A. relay closes, the control
allows for this delay to receive the proof demand. If the proof
demand is not received within the delay time, the control
will display an error message.
Combustion Air Delay Setting in Adjust Menu
If the Proof Demand function is set to F P (flow proof) or
OFF, sequencing only occurs once a user adjustable time
delay elapses.
Combustion Air Post Purge
There is a fixed 15 second post purge of the C.A. relay
after the last boiler has turned off, or demand is removed. If
there is a heat demand still present once the last boiler has
turned off, the control can look at the error and determine
if sequencing is to occur in a “short” period of time. If the
control does anticipate staging, the C.A. relay will remain
on. Otherwise, the C.A. relay will be turned off once the 15
second post purge elapses.
Page 19
•
••
••
•
•
•
•
•
•
Combustion Air Proof Demand Test
The control includes a C.A. proof demand test in order to
determine if the proving device has failed. If the C.A. damper
contacts are opened, the flow proof demand should not be
present after 4 minutes. If the flow proof demand remains,
the control will display an error message.
Setting the Schedule Section N
To provide greater energy savings, you can operate the
control on a programmable schedule. The schedule is
stored in memory and is not affected by loss of power to the
control. If a tN4 network is detected the control can become
either a schedule member or schedule master.
Control (CTRL) Schedule (tN4 present)
The schedule only applies to the control. The control follows
its own schedule and the events are not communicated to
tN4 thermostats.
Master Schedule (tN4 present)
If the control is connected to tN4 thermostats, then the
control can operate on a master schedule. You can set up
a maximum of four master schedules on the tN4 Network.
A master schedule is available to all devices on the tN4
network. Master schedules simplify installation since one
master schedule may be used by multiple devices.
To create a master schedule:
Assign the control to be a schedule master by setting
•
the Heat Schedule item in the Schedule menu to Master
(MST) 1 to 4. After a master schedule is selected, a clock
symbol will appear in the View menu display.
Note: The 275 Setback / Off DIP Switch must be set to
Setback to access the Schedule Menu.
To follow a master schedule:
Assign the control to follow a master schedule by setting
•
the Heat Schedule in the Schedule menu to Member
(MBR) 1 to 4.
Member of
Schedule 1
Master
Schedule 1
None
Zone
Schedule
Master
Schedule 2
Members of
Schedule 2
Schedule Types
The schedule type determines when the schedule repeats
itself. This control includes three schedule types:
• 24 Hour: Repeats every 24 hours.
• 5-11: Repeats on a weekly basis. However, it breaks the
week into Saturday and Sunday followed by the weekdays.
This reduces the amount of schedule event settings.
• 7 Day: Repeats on a weekly basis and allows for separate
event times for each day.
Schedule Type
Day24 Hour5-117 day
Saturday
Sunday
Monday
Tuesday
Wednesday
Thursday
Friday
Schedule Mode
The schedule mode can have either 4 or 2 events per day.
An event is a time at which the control changes the target
temperature. The event time can be set to the nearest 10
minutes. If you wish to have the thermostat skip the event,
enter “--:--“ as the time. The “--:--“ time is found between
11:50 PM and 12:00 AM. See the table, Schedule Mode,
for more details regarding types of events.
275
Zone 1
23 4 56
Schedule Mode Event24HrSatSunMonTueWeThuFri
6:00 AM6:00 AM6:00 AM6:00 AM6:00 AM6:00 AM6:00 AM6:00 AM
8:00 AM8:00 AM8:00 AM8:00 AM8:00 AM8:00 AM8:00 AM8:00 AM
The control will exercise the Combustion Air Damper, all
pumps, and tN4 zones (zone valves and zone pumps) for
10 seconds every three days of inactivity to prevent seizure.
To enable exercising, switch the Exercise / Off DIP to the
Exercise position.
Daylight Savings Time Modes
ModeDST StartDST End
11st Sunday in AprilLast Sunday in October
22nd Sunday in March1st Sunday in November
The control has a built-in time clock to allow the control to
operate on a schedule. A battery-less backup allows the
control to keep time for up to 4 hours without power. The
time clock supports automatic adjustment for Daylight
Saving Time (DST) once the day, month, and year are
entered. Use the Time menu to set the correct time, day,
month, and year.
Note: The Setback / Off DIP Switch must be set to Setback
before the Time menu can be accessed.
Boost Section P
When the control changes from the UnOccupied mode
to the Occupied mode, it enters into a boosting mode. In
this mode, the supply water temperature to the system
is raised above its normal values for a period of time to
provide a faster recovery from the setback temperature of
the building. The maximum length of the boost is selected
using the BOOST setting in the Adjust menu.
Typical settings for the boost function vary between 30
minutes and two hours for buildings that have a fast
responding heating system. For buildings that have a
slow responding heating system, a setting between four
hours and eight hours is typical. After a boost time is
selected, the setback timer must be adjusted to come out
of setback some time in advance of the desired occupied
time. This time in advance is normally the same as the
BOOST setting.
If the building is not up to temperature at the correct time,
the BOOST setting should be lengthened and the setback
timer should be adjusted accordingly. If the building is
up to temperature before the required time, the BOOST
setting should be shortened and the setback timer should
be adjusted accordingly. If the system is operating near
its design conditions or if the supply water temperature
is being limited by settings made in the control, the time
required to bring the building up to temperature may be
longer than expected.
Exercising Section Q
The control will exercise the Combustion Air Damper, all
pumps, and tN4 zones (zone valves and zone pumps) for
10 seconds every three days of inactivity to prevent seizure.
To enable exercising, switch the Exercise / Off DIP to the
Exercise position.
tekmarNet®4 Communication Section R
tekmarNet®4 (tN4) communicates between tN4 devices
(thermostats, Reset Module and Expansion Modules). Each
tN4 device is connected to a tN4 communication bus using
two wires. Each tN4 bus adjusts a single water temperature
in the system using indoor temperature feedback. The
Boiler Control 275 allows for one tN4 bus. This allows you
to control a system with one water temperature. A system
that has more than one tN4 bus is referred to as a tN4
network.
Network
Bus 1
275
tekmarNet®4
Thermostats
Boiler Control 275
The Boiler Control 275 is the system control for a hydronic
heating system. The 275 operates up to 4 modulating boilers,
a domestic hot water tank, and responds to other heating
requirements such as pool heating and snow melting. The
275 also coordinates and optimizes the operation of all the
tN4 thermostats.
tN4 Thermostat
The tN4 thermostat operates heating, cooling, and or
ventilation equipment for a zone. Several tN4 thermostats
may work in a group when operating a cooling system. Up
to 24 tN4 devices can connect to a single tN4 bus.
Zone load shedding helps protect non-condensing boilers
from sustained flue gas condensation damage. Zone load
shedding starts when the boiler supply temperature is below
the boiler minimum setting and all boilers are operating
at 100% output. Zones are shut off in order of their tN4
address.
Second stage heat zones are the first to shut off starting
with thermostat address b:24, continuing downward until
the last to shut off is b:01.
Once all second stage heat zones are shut off, first stage
zones shut off starting with highest thermostat address b:24
and ending at the lowest b:01.
When the boiler supply temperature reaches the boiler
minimum, the first stage heating zones turn back on in
order from b:01 to b:24, and then the second stage in order
from b:01 to b:24.
Cycle Length Setting in Adjust Menu (tN4)
The control includes an adjustment for the cycle length.
The cycle length adjustment allows for synchronization of
tN4 zones. An Auto setting allows for the cycle length to
be automatically calculated to balance equipment cycling
and comfort.
In the tekmarNet®4 system, all of the tekmarNet®4
Thermostats determine the best cycle length for their
zone. The thermostats look at trying to maintain the longest
possible cycle length while keeping temperature swings to
a minimum. The Thermostats do this every cycle and send
their ideal cycle length time to the 275.
In order to operate the system as efficiently as possible, all of
the zones must operate based on the same cycle. In order to
do this, the 275 listens to all of the cycle length requests from
all of the tekmarNet®4 Thermostats. The 275 then determines
the average cycle length and sends this information to all of
the tekmarNet®4 Thermostats, allowing them to operate on
the same cycle.
Indoor Temperature Feedback (tN4)
Indoor feedback applies when the 275 is connected to a
tN4 Thermostat network operating on a boiler bus. Indoor
temperature feedback fine tunes the water temperature of
the system based on the requirements of the thermostats.
Each thermostat tells the tN4 System Control the water
temperature that it requires to heat its zone.
If the zone is becoming too cool, the thermostat asks for
•
a higher water temperature.
If the zone is becoming too warm, the thermostat asks for
•
a cooler water temperature.
The 275 provides the highest water temperature required
by all of the thermostats.
The thermostat with the highest water temperature
•
requirement stays on 100% of its cycle.
The remaining thermostats stay on for a percentage of
•
their cycles.
100%
On Time
Reset Water
Temperature
85%
On Time
90%
On Time
Device Count (tN4)
The control includes a device count of all the tN4 devices
connected to the boiler bus. This item is always found in
the Miscellaneous Menu called NUM DEV. Use this to
confirm that the correct number of devices are connected
to the boiler bus.
Scene Operation Section S
The 275 can be connected to a User Switch using
tekmarNet® communication and responds to the following
scenes.
Improper installation and operation of this control could
result in damage to the equipment and possibly even
personal injury or death. It is your responsibility to ensure
that this control is safely installed according to all applicable
codes and standards. This electronic control is not intended
for uses as a primary limit control. Other controls that are
intended and certified as safety limits must be placed into
the control circuit. Do not attempt to service the control.
Refer to qualified personnel for servicing. Opening voids
warranty and could result in damage to the equipment and
possibly even personal injury or death.
Step One — Getting Ready
Check the contents of this package. If any of the contents listed
are missing or damaged, please contact your wholesaler or
tekmar sales representative for assistance.
Type 275 includes:
One Boiler Control 275, One Outdoor Sensor 070, Two
Universal Sensors 082, One 500 Ohm resistor, Data Brochures
D 275, D 070, D 001, Application Brochure A 275.
Note: Carefully read the details of the Sequence of
Operation to ensure the proper control was chosen for
the application.
Step Two — Mounting the Base
Remove the control from its base by pressing on the release clip in the wiring chamber and sliding the control away from it.
The base is then mounted in accordance with the instructions in the Data Brochure D 001.
Step Three — Rough-in Wiring
All electrical wiring terminates in the control base wiring
chamber. The base has standard 7/8” (22 mm) knockouts,
which accept common wiring hardware and conduit fittings.
Before removing the knockouts, check the wiring diagram
and select those sections of the chamber with common
voltages. Do not allow the wiring to cross between sections
as the wires will interfere with safety dividers which should
be installed at a later time.
Power must not be applied to any of the wires during the
rough-in wiring stage.
All wires are to be stripped to a length of 3/8” (9 mm) to
•
ensure proper connection to the control.
Install the Outdoor Sensor 070 according to the installation
•
instructions in the Data Brochure D 070 and run the wiring
back to the control.
Install the Boiler Supply Sensor 082 according to the
•
installation instructions in the Data Brochure D 070 and
run the wiring back to the control.
Install the Boiler Return or DHW Sensor 082 according
•
to the installation instructions in the Data Brochure D 070
and run the wiring back to the control.
Run wires from any security system, alarm panel, or
•
telephone dialer back to the control.
Run wires from other system components (boilers, pumps,
•
flow switch, etc.) to the control.
Run wires from the 115 V (ac) power to the control. Use
•
a clean power source with a 15 A circuit to ensure proper
operation. Multi-strand 16 AWG wire is recommended for
all 115 V (ac) wiring due to its superior flexibility and ease
of installation into the terminals.
The installer should test to confirm that no voltage is present at any of the wires. Push the control into the base and slide
it down until it snaps firmly into place.
Powered Input ConnectionsTerminals 25 - 31
25 26
115 V (ac) Power
Connect the 115 V (ac) power supply to the Power L and
Power N terminals (25 and 26). This connection provides
power to the microprocessor and display of the control.
Boiler Demand
To generate a Boiler Demand, a voltage between 20 V (ac)
and 260 V (ac) must be applied across the Boiler Demand
terminals (27 and 28).
DHW Demand
To generate a DHW Demand, a voltage between 20 V (ac)
and 260 V (ac) must be applied across the DHW/Setp and
Com Dem terminals (29 and 30). The Pump Sequencer
DIP Switch must be set to Off and DHW MODE must be
set to 1 through 5.
115 V (ac)
L
N
20 to 260
V (ac)
20 to 260
V (ac)
L
N
L
N
Power
LN
2827
Boiler
Demand
313029
Pr.ComDHW
DemDem/Setp
Setpoint Demand
To generate a Setpoint Demand, a voltage between 20 V
(ac) and 260 V (ac) must be applied across the DHW/Setp
313029
Pr.ComDHW
DemDem/Setp
and Com Dem terminals (29 and 30). The DHW MODE
must be set to OFF.
Proof Demand
20 to 260
V (ac)
L
N
313029
Pr.ComDHW
DemDem/Setp
To generate a Proof Demand, a voltage between 20 V (ac)
and 260 V (ac) must be applied across the Pr. Dem and
Com Dem terminals (31 and 30).
Energy Management System (EMS)
To generate an external input signal from an Energy
20 to 260
V (ac)
N
L
32
OutCom
+
-
Management System (EMS), either a 0 to 10 V (dc) or 2
to 10 V (dc) signal must be applied to the Com – and Out
+ terminals (2 and 3).
A 0 - 20 mA signal can be converted to a 0 - 10 V (dc) signal
by installing a 500 resistor in parallel between the Com
– and Out + terminals (2 and 3).
A 4 - 20 mA signal can be converted to a 2 - 10 V (dc) signal
by installing a 500 resistor in parallel between the Com
– and Out + terminals (2 and 3).
Terminals 1 and 2 provide a tN4 connection for tN4 devices
on the tN4 bus. Connect terminals 1 (tN4) and 2 (Com) to
the corresponding terminals on the tN4 devices that are
tN4
Device
ComtN4
ComtN4
to be connected.
Note: The connection is polarity sensitive. Ensure that
terminal 1 (tN4) is connected to the tN4 terminal on the tN4
device and that terminal 2 (C) is connect to the C terminal
on the tN4 device.
Outdoor Sensor (tekmar 070)
Connect the two wires from the Outdoor Sensor 070
-
to the Com and Out (2 and 3) terminals. The outdoor
sensor is used by the control to measure the outdoor air
temperature.
Outdoor
Sensor
070
Note: If an Outdoor Sensor 070 is connected to a
tekmarNet®4 thermostat in the system, it is not required
to be connected to the control.
Boiler Supply Sensor (tekmar 082)
Connect the two wires from the Boiler Supply Sensor 082
to the Com and Boil (5 and 4) terminals. The Boiler Supply
Boiler Supply Sensor 082
ComBoil
Sup
Sensor is used by the control to measure the boiler supply
water temperature.
21
-
32
OutCom
+
54
DHW or Boiler Return Sensor (tekmar 082)
Connect the two wires from the DHW Sensor 082 to the
Com and BRet / DHW (5 and 6) terminals. The DHW
Sensor is used by the control to measure the DHW water
temperature or the DHW Exchange Supply Temperature.
OR
DHW Sensor 082
OR
Boiler Return Sensor 082
BRet/Com
DHW
Connect the two wires from the Boiler Return Sensor 082
to the Com and BRet / DHW (5 and 6) terminals. The Boiler
Return Sensor is used by the control to measure the boiler
return temperature.
Powered Output Connections Terminals 23 - 26
Primary Pump P1
The Prim P1 output on terminal (24) is a powered output.
When the relay in the control closes, 115 V (ac) is provided
to the Prim P1 terminal (24) from the Power L terminal (25).
To operate the primary pump P1, connect one side of the
primary pump circuit to terminal (24) and the second side
of the pump circuit to the neutral (Power N) side of the 115
V (ac) power supply.
Primary
Pump
Pump
Pump
L & N
L
N
24 25 26
Prim Power
P1 LN
65
Primary Pump P2
The DHW / P2 output on terminal (23) is a powered output.
When the relay in the control closes, 115 V (ac) is provided
to the DHW / P2 terminal (23) from the Power L terminal
(25). To operate the primary pump P2, connect one side
of the primary pump circuit to terminal (23) and the second
side of the pump circuit to the neutral (Power N) side of the
115 V (ac) power supply.
The control provides a 0-10 V (dc) modulating output to
four modulating boilers.
• Polarity is important.
• Connect the + wire from boilers 1, 2, 3 and 4 to terminals
7, 9, 10 and 12 respectively.
• Connect the – wire from boilers 1 and 2 to terminal 8 and
from boilers 3 and 4 to terminal 11.
Note: Some modulating boilers may also require an on / off
signal in addition to the modulating signal. See terminals
13 to 20.
Wiring the T-T
(RELAY TYPE = Boiler )
Terminals 13-14, 15-16, 17-18 and 19-20 are dry contacts.
No power is available from these terminals. These contacts
can be used to enable the modulating or on/off boiler. The
boiler must be wired to power as per the manufacturers’
directions.
These terminals are typically connected to the boiler’s
control circuit (commonly labeled as T-T). Connect these
terminals directly to the boiler T-T connections.
Modulating
Boiler 1
Modulating
Boiler 2
Modulating
Boiler 3
Modulating
Boiler 4
789101112
Mod1
-
+
-
+
-
+
-
+
Mod2
Mod3
+
-
++
Mod4
-
+
2019181716151413
RelayRelayRelayRelay
4321
Wiring the Boiler Pumps
(RELAY TYPE = Boiler pump )
Terminals 13-14, 15-16, 17-18 and 19-20 are dry contacts.
No power is available from these terminals. These contacts
can be used to turn on individual boiler pumps. Wire line
voltage to one side of the relay. The other side of the relay
goes to one side of the boiler pump and the remaining side
of the boiler pump goes to neutral.
Combustion Air / Alert Contact (C.A./Alert)
Terminals 21 and 22 are an isolated output in the control.
There is no power available on these terminals from the
control. These terminals are to be used as a switch to either
make or break power to the combustion air damper or alert
device. Since this is an isolated contact, it may switch a
voltage between 24 V (ac) and 230 V (ac).
The following tests are to be performed using standard
testing practices and procedures and should only be carried
out by properly trained and experienced persons.
A good quality electrical test meter, capable of reading from
at least 0-300 V (ac), 0-30 V (dc), 0-2,000,000 Ohms, and
testing for continuity is essential to properly test the wiring
and sensors.
Testing tN4 Network Terminals 1 – 2
To test the tN4 Network, check the wires for continuity.
1. Disconnect the two wires (tN4 and Com) at one end and
connect them together.
2. Go to the other end of the wires and disconnect them.
3. Using an electrical test meter, check for continuity.
###
tN4
Device
tN4
Com
Boiler
Control
275
32
OutCom
+
-
ComtN4
21
-
Testing the EMS output Terminals 2 – 3
If an Energy Management System is used, measure the
voltage (dc) between the Com – and the Out + terminals
(2 and 3). When the EMS calls for heat, a voltage between
0 – 10 V (dc) or 2 – 10 V (dc) should be measured at the
terminals.
Testing the Sensor WiringTerminals 2 – 6
To test the sensors, the actual temperature at each sensor
location must be measured.
Disconnect each sensor from the control.
Use a good quality digital thermometer with a surface
•
temperature probe for ease of use and accuracy. Where
a digital thermometer is not available, strap a spare
•
Test the sensors resistance according to the instructions
•
in the sensor Data Brochure D 070.
sensor alongside the one to be tested and compare
the readings.
Testing Modulating Outputs (0-10 V dc) Terminals 7 – 12
1. Ensure that the control can operate the modulating output
by setting at least one boiler to Auto
2. Remove the front cover from the control.
3. Press the Test Button.
4. When the % output and the boiler symbol are displayed
in the LCD, use an electrical test meter to measure the
(dc) voltage between the appropriate Mod + and the
- terminals (7-8, 8-9, 10-11, 11-12). The reading should
vary between 0 V (dc) and 10 V (dc).
1. Shut off power to the control and the boiler circuit or
boiler pump circuit.
2. Remove the bottom cover from the control. Disconnect
the wiring from the Relay contacts (terminals 13 – 20).
3. Apply power to the control and press the Test button.
4. Use an electrical test meter and check for continuity
between terminals 13 - 14, 15 - 16, 17 - 18, and 19 - 20.
If the relay is set to boiler pump:
•
When the appropriate boiler pump symbol is displayed
•
in the LCD, there should be continuity.
When the appropriate boiler pump symbol is not displayed
•
in the LCD, there should be no continuity.
5. Reconnect the wires to the Relay contacts, install the
bottom cover on the control and reapply power to the
boiler circuit or boiler pump circuit.
If the relay is set to boiler ignition:
When the appropriate boiler symbol is displayed in the
•
LCD, there should be continuity.
When the appropriate boiler symbol is not displayed in
•
the LCD, there should be no continuity.
Testing C.A. / Alert Relay Terminals 21 – 22
1. Shut off power to the control and the boiler circuit or
boiler pump circuit.
2. Remove the bottom cover from the control. Disconnect the
wiring from the C.A. / Alert contact (terminals 21 – 22).
3. Apply power to the control and press the Test button.
4. Use an electrical test meter and check for continuity
between terminals 21 – 22.
If the relay is set to Combustion Air Damper:
When the Combustion Air Damper symbol is displayed
•
in the LCD, there should be continuity.
When the Combustion Air Damper symbol is not displayed
•
in the LCD, there should be no continuity.
If the relay is set to Alert:
When the Alert symbol is displayed in the LCD, there
•
should be continuity.
When the Alert symbol is not displayed in the LCD, there
•
should be no continuity.
5. Reconnect the wires to the C.A. / Alert contacts, install
the bottom cover on the control and reapply power to
the Combustion Air Damper or Alert circuit.
Testing DHW and Primary Pumps Terminals 23 - 24
1. Remove the front and bottom covers from the control.
2. Press the Test Button.
3. When the Primary Pump 1 symbol is displayed in the LCD,
use an electrical test meter to measure the (ac) voltage
between the Primary Pump 1 terminal and Neutral (24-
26). The reading should be 115 V (ac) + / – 10%.
If DHW Mode is enabled:
When the DHW Pump symbol is displayed in the LCD, use
an electrical test meter to measure the (ac) voltage between
the DHW Pump terminal and Neutral (23-26). The reading
should be 115 V (ac) + / – 10%.
If Pump Sequencer is enabled:
When the Primary Pump 2 symbol is displayed in the LCD,
use an electrical test meter to measure the (ac) voltage
between the Primary Pump 2 terminal and Neutral (23-26).
The reading should be 115 V (ac) + / – 10%.
Testing the Input Power Terminals 25 – 26
1. Remove the front and bottom cover from the control.
2. Use an electrical test meter to measure (ac) voltage
between the Input Power L and N terminals (25 and 26).
The reading should be 115 V (ac) + / – 10% and the LCD
should be lit and show some segments.
3. If power is not present and the LCD is off:
Check the circuit that supplies power to the Control.
•
Make sure exposed wires and bare terminals are not in
•
contact with other wires or grounded surfaces.
Testing the Demands Terminals 27 – 31
1. Remove the front and bottom cover from the control.
2. Use an electrical test meter to measure (ac) voltage
between the Boiler Demand terminals (27-28) or the
DHW / Setpoint Demand terminals (29-30) or the Proof
Demand terminals (30-31).
When the demand device is on, a voltage between
•
20 and 260 V (ac) should be measured between the
appropriate demand terminals and the LCD should display
an indicator arrow pointing to Boiler Demand, DHW /
Setpoint Demand, or Proof Demand.
When the demand device is off, less than 5 V (ac) should
The control’s exterior can be cleaned using a damp cloth. Moisten the cloth with water and wring out prior to wiping control.
Do not use solvents or cleaning solutions.
DIP Switch Settings
Set the DIP switch settings prior to making adjustments
to the control through the user interface. Setting the DIP
switches determines which menu items are displayed in
the user interface.
Switch Settings
Pump Sequencer
Setback
BTC IOffEMS
Fixed Last
Off
Rotate
Fixed Lead
Exercise
Demands
Made in Canada by
tekmar Control Systems Ltd
tektra 1020-01
Power 115 V ±10% 60 Hz 7 VA, 1150 VA max.
Relays 230 V (ac) 5 A 1/3 hp
Demands 20 to 260 V (ac) 2 VA
Signal wiring must be rated at least 300 V.
26
24
23 251615 1817 2019 2221
Prim
Power
DHW
P1 L N
/ P2
Alert
First On / Last Off
First On / First Off
Test
off
not testing
red
testing
red
testing paused
For maximum heat,
press and hold Test
button for 3 seconds.
Meets Class B:
Canadian ICES
FCC Part 15
Date Code
29
30
31
28271413
DHW
Boiler
Com
Pr.
H2048B
Demand
/Setp
Dem
Dem
Menu Item
Boiler Control 275
One tN4, Four Modulating Boiler & DHW / Setpoint
Do not apply power
2–5
1
3
4
6
7
9
11
BRet/
Mod1
Mod2
Mod3
Com8tN4
Out10Com
Boil
+
+–+
+
DHW
–
Sup
Boiler Demand
DHW / Setpoint Demand
Proof Demand
Zone Load Shedding
Priority Override
EMS Input Signal
12
Mod4
Relay1Relay2Relay3Relay4C.A. /
+
EMS / Demands
The EMS / Demands DIP switch selects whether a tekmar
outdoor sensor 070 or an external 0-10 or 2-10 V (dc) input
signal is to be connected to the com - and Out+ terminals
(2 & 3).
Set the EMS / Demands DIP switch to EMS if an Energy
Management System is providing an external analog input
signal to the control.
Set the EMS / Demands DIP switch to Demands if the
control is accepting a boiler demand and using the outdoor
sensor for outdoor reset.
EMS
Demands
Setback BTC I
Rotate
Off
Exercise
Off
Pump Sequencer
Fixed Last
Fixed Lead
First On / Last Off
First On / First Off
Lock / Unlock
Use this DIP switch to lock and unlock the Access Level
of the 275 and all connected tN4 devices, including tN4
thermostats. For details, see “Access Level”.
• Once locked, the access level in all devices cannot be
viewed or changed.
• When the control is locked, a small segment representing
a padlock is shown in the bottom right hand corner of the
display (except in View and Time Menu)
EMS
Demands
Setback BTC I
Rotate
Off
Exercise
Off
Pump Sequencer
Fixed Last
Fixed Lead
First On / Last Off
First On / First Off
Off / Exercise
Use the Off / Exercise DIP switch to select whether or not
the control is to exercise all pumps, and hydronic zones
(zone valves and zone pumps) for 10 seconds every three
days of inactivity to prevent seizure.
EMS
Demands
Setback BTC I
Rotate
Off
Exercise
Off
Pump Sequencer
Fixed Last
Fixed Lead
First On / Last Off
First On / First Off
Setback / Off
Use the Setback / Off DIP switch to select whether or not
the control is to follow a schedule.
If the 275 is to be a schedule member or schedule master,
•
set the DIP switch to Setback to enable the Time and
Schedule menus and the Unocc items in the Adjust
menu.
If the 275 does not follow a schedule, set the DIP switch
•
to Off to disable the Time and Schedule menus and the
Unocc items in the Adjust menu.
Use the Rotate / Off DIP switch to enable the Equal Run
Time Rotation feature. This feature Changes the firing
order of the boilers in order to maintain a similar amount of
running time on each boiler. If set to Off, the firing sequence
if fixed starting with boiler 1 to boiler 4.
EMS
Exercise
Demands
Setback BTC I
Rotate
Off
Off
Pump Sequencer
Fixed Last
Fixed Lead
First On / Last Off
First On / First Off
BTC I / Off
Use the BTC I / Off DIP switch when the 275 is wired to
boilers with BTC I (Boiler Temperature Control series I)
controls.
If wired to BTC I controls, set the DIP switch to BTC I.
•
If not wired to BTC I controls, set the DIP switch to Off.
•
EMS
Exercise
Demands
Setback BTC I
Rotate
Off
Off
Pump Sequencer
Fixed Last
Fixed Lead
First On / Last Off
First On / First Off
Pump Sequencer / Off
Use the Pump Sequencer / Off DIP switch to activate
primary pump sequencing. DHW operation is not available
when Pump Sequencer is selected.
If set to Pump Sequencer, the control operates primary
•
pumps 1 & 2 in stand-by mode.
If set to Off, the control operates primary pump 1 and the
•
pump 2 relay is then available for a DHW pump.
EMS
Exercise
Demands
Setback BTC I
Rotate
Off
Off
Pump Sequencer
Fixed Last
Fixed Lead
First On / Last Off
First On / First Off
Fixed Last / Off
Use the Fixed Last / Off DIP switch to exclude the last boiler
in the rotation sequence. This DIP is only active when the
Rotate / Off DIP is set to Rotate.
If set to Fixed Last, the last boiler is always the last to fire.
•
Fixed Last will only work for boilers wired to the Relay 4
•
terminals (19 and 20).
EMS
Exercise
Demands
Setback BTC I
Rotate
Off
Off
Pump Sequencer
Fixed Last
Fixed Lead
First On / Last Off
First On / First Off
Fixed Lead / Off
Use the Fixed Lead / Off DIP switch to exclude the first
•
boiler in the rotation sequence. This DIP is only active
when the Rotate / Off DIP is set to Rotate.
If set to Fixed Lead, the first boiler is always the first to fire.
•
Fixed Lead will only work for boilers wired to the Relay 1
•
terminals (13 and 14).
EMS
Exercise
Demands
Setback BTC I
Rotate
Off
Off
Pump Sequencer
Fixed Last
Fixed Lead
First On / Last Off
First On / First Off
First On / Last Off or First On / First Off.
The First On / Last Off or First On / First Off DIP switch
•
selects whether the first boiler is the first to fire and the
last to shut off or the first to fire and the first to shut off.
This DIP switch is only active when the Rotate / Off DIP
switch is set to Rotate and the Fixed Lead / Off DIP switch
The View menu items display the current operating
temperatures and status information of the system.
Item FieldRange
VIEW
VIEW
VIEW
VIEW
VIEW
VIEW MENU
VIEW
-76 to 149°F
(-60.0 to 65.0°C)
-22 to 266°F
(-30.0 to 130.0°C)
---, 35 to 230°F
(---, 1.5 to 110.0°C)
---, 35 to 230°F
(---, 1.5 to 110.0°C)
-22 to 266°F
(-30.0 to 130.0°C)
-22 to 266°F
(-30.0 to 130.0°C)
Access
USER
INST
ADV
USER
INST
ADV
ADV
ADV
USER
INST
ADV
ADV
Description
OUTDOOR
Current outdoor air temperature as measured by
the outdoor sensor.
Note: This item is only available when the EMS/
Demands DIP is set to Demands.
BOILER SUPPLY
Current boiler supply water temperature as
measured by the boiler sensor.
Note: This item is not available when DHW Mode is 6.
BOILER TARGET SECTION C
The boiler target is the temperature the control
is currently trying to maintain at the boiler supply
sensor. “---” is displayed when no heat is required.
Note: This item is not available when DHW Mode is 6.
DHW EXCHANGE TARGET SECTION I
The DHW exchange target is the temperature the
control is currently trying to maintain at the DHW
Exchange Supply Sensor. “- - -” is displayed when
no heat is required.
Note: This item is only available when DHW Mode is 5.
DHW SECTION I
Current DHW tank temperature as measured by the
DHW sensor.
Note: This item is only available if DHW Sensor
is On and Pump Sequencing DIP is Off, or DHW
Mode is 6.
BOILER RETURN
Current boiler return water temperature as measured
by the boiler return sensor.
Note: This item is only available if DHW Sensor is Off
and a boiler return sensor is present.
Current temperature difference between the boiler
supply and boiler return sensors.
Note: This item is only available if DHW
Sensor is Off and a boiler return sensor is present.
BOILER 1 MODULATION / STG SECTION D
Current percent modulation of the boiler 1 burner.
If the BTC I / Off DIP is set to BTC I, the BTC I
number of stages is displayed.
Note: This item is only available when boiler 1 is
set to Auto.
Page 31
View Menu (2 of 2)
Item FieldRange
VIEW
2
VIEW
3
VIEW
4
VIEW
hr
1
0 to 9999 hours
0 to 100 %
or
1 to 4
0 to 100%
or
1 to 4
0 to 100%
or
1 to 4
Access
ADV
ADV
ADV
ADV
Description
BOILER 2 MODULATION / STG
SECTION D
Current percent modulation of the boiler 2 burner.
If the BTC I / Off DIP is set to BTC I, the BTC I
number of stages is displayed.
Note: This item is only available when boiler 2 is
set to Auto or CP1.
BOILER 3 MODULATION / STG SECTION D
Current percent modulation of the boiler 3 burner. If
the BTC I / Off DIP is set to BTC I, the BTC I number
of stages is displayed.
Note: This item is only available when boiler 3 is set
to Auto or CP1.
BOILER 4 MODULATION / STG SECTION D
Current percent modulation of the boiler 4 burner. If
the BTC I / Off DIP is set to BTC I, the BTC I number
of stages is displayed.
Note: This item is only available when boiler 4 is set
to Auto or CP1.
BOILER 1 RUNNING TIME SECTION C
The total running time of boiler 1 since this item was
last cleared. To clear this item, press the up and down
buttons together while viewing this item. Note: This
item is only available when boiler 1 is set to Auto.
VIEW
hr
2
VIEW
VIEW MENU
hr
3
VIEW
hr
4
VIEW
hr
1
Primary
VIEW
hr
2
Primary
0 to 9999 hours
0 to 9999 hours
0 to 9999 hours
0 to 9999 hours
0 to 9999 hours
ADV
ADV
ADV
ADV
ADV
After the last item, the control returns to the first item in the menu.
BOILER 2 RUNNING TIME SECTION C
The total running time of boiler 2 since this item was
last cleared. To clear this item, press the up and down
buttons together while viewing this item. Note: This item
is only available when boiler 2 is set to Auto or CP1.
BOILER 3 RUNNING TIME SECTION C
The total running time of boiler 3 since this item was
last cleared. To clear this item, press the up and down
buttons together while viewing this item. Note: This item
is only available when boiler 3 is set to Auto or CP1.
BOILER 4 RUNNING TIME SECTION C
The total running time of boiler 4 since this item was
last cleared. To clear this item, press the up and down
buttons together while viewing this item. Note: This item
is only available when boiler 4 is set to Auto or CP1.
PRIMARY PUMP 1 RUNNING TIME SECTION L
The total running time of pump 1 since this item was
last cleared. To clear this item, press the up and down
buttons together while viewing this item.
PUMP 2 RUNNING TIME SECTION L
The total running time of pump 2 since this item was
last cleared. To clear this item, press the up and down
buttons together while viewing this item.
Note: This item is only available when the Pump
Sequencer / Off DIP Switch is set to Pump
Sequencer.
The Adjust Menu items are the programmable settings used
to operate the mechanical equipment.
ADJUST
ADJUST
ADJUST
ADJUST
Occ
UnOcc
35 to 100°F
(2.0 to 38.0°C)
Default = 70°F
(21.0°C)
35 to 100°F
(2.0 to 38.0°C)
Default = 70°F
(21.0°C)
0-10, 2-10
Default = 0-10
-10 to 10°F
(-5.6 to 5.6°C)
Default = 0°F
(°C)
INST
ADV
INST
ADV
ADV
ADV
ROOM OCCUPIED SECTION B
The desired room air temperature during the
occupied period. Note: This item is only available
when EMS / Demands DIP is set to Demands
and Outdoor Design is set to a temperature.
ROOM UNOCCUPIED SECTION B
The desired room air temperature during the
unoccupied period. Note: This item is only
available when EMS / Demands DIP is set
to Demands and Outdoor Design is set to a
temperature. and the Setback / Off DIP switch
is set to Setback.
EMS SIGNAL SECTION K
Selects the range of the Energy Management
System (EMS) input signal. Note: This item is
only available when the EMS / Demands DIP
switch is set to EMS.
OFFSET SECTION K
Selects the range of the Energy Management
System input signal. Note: This item is only
available when the EMS / Demands DIP switch
is set to EMS.
ADJUST
ADJUST MENU
ADJUST
ADJUST
ADJUST
OFF, 0:20 to
8:00 hr
(5 minute incre-
ADV
ments)
Default = OFF)
Auto, OFF
Default = Auto
1
INST
ADV
Mod, OnOF
or
1, 2, 3, 4, Mod
1
Default = Mod
ADV
BOOST SECTION P
The maximum amount of morning boost when
changing from the unoccupied to the occupied
period. Note: This item is only available when
EMS / Demands DIP is set to Demands and
Setback / Off DIP is set to Setback.
BOILER 1
SECTION C
Selects whether boiler 1 is operational or not.
BOILER 1 MODE SECTION D, E, F
Select whether boiler 1 is modulating (Mod) or
on-off (OnOF). If the BTC I / Off DIP switch is
set to BTC I, then select the number of boiler
stages for boiler 1.
BOILER 2 SECTION C
CP1, Auto, OFF
Default = Auto
2
INST
ADV
Selects whether boiler 2 is operational or not.
CP1 copies the settings of boiler 1 to boiler 2
and selects boiler 2 to be operational.
Select whether boiler 2 is modulating (Mod) or
on-off (OnOF). If the BTC I / Off DIP switch is
set to BTC I, then select the number of boiler
stages for boiler 2.
SECTION D, E, F
BOILER 3 SECTION C
CP1, Auto, OFF
Default = Auto
3
Mod, OnOF
or
1, 2, 3, 4, Mod
3
Default = Mod
INST
ADV
ADV
Selects whether boiler 3 is operational or not.
CP1 copies the settings of boiler 1 to boiler 3
and selects boiler 3 to be operational.
BOILER 3 MODE SECTION D, E, F
Select whether boiler 3 is modulating (Mod) or
on-off (OnOF). If the BTC I / Off DIP switch is
set to BTC I, then select the number of boiler
stages for boiler 3.
BOILER 4 SECTION C
CP1, Auto, OFF
Default = Auto
INST
ADV
Selects whether boiler 4 is operational or not.
CP1 copies the settings of boiler 1 to boiler 4
and selects boiler 4 to be operational.
Mod, OnOF
or
1, 2, 3, 4, Mod
Default = Mod
ADV
BOILER 4 MODE SECTION D, E, F
Select whether boiler 4 is modulating (Mod) or
on-off (OnOF). If the BTC I / Off DIP switch is
set to BTC I, then select the number of boiler
stages for boiler 4.
ADJUST
ADJUST MENU
OFF, -60 to
45°F
(OFF, -51 to
7.0°C)
Default = 10°F
(-12°C)
INST
ADV
OUTDOOR DESIGN SECTION B
The design outdoor air temperature used in the
heat loss calculations for the heating system.
Typically set to the outdoor temperature of the
coldest day of the year. When set to OFF, the
boiler target is fixed to 180°F (82.0°C).
HRF1
ADJUST
HRF2
COIL
CONV
RAD
BASE
INST
ADV
TERMINAL SECTION B
The type of heating terminal units that are being used.
Note: This item is only available when the
EMS / Demands DIP switch is set to Demands
and outdoor design is set to a temperature.
Default = CONV
BOILER INDOOR SECTION B
ADJUST
35 to 100°F
(2.0 to 38.0°C)
Default = 70°F
(21.0°C)
ADV
The design indoor air temperature used
in the heat loss calculation for the boiler
zones. Typically set to 70°F (21.0°C).
Note: This item is only available when the
EMS / Demands DIP switch is set to Demands
and outdoor design is set to a temperature.
BOILER DESIGN SECTION B
The supply water temperature required for
boiler zones on the typical coldest day of the
year. Note: This item is only available when the
EMS / Demands DIP switch is set to Demands
and outdoor design is set to a temperature.
Select whether or not the lead group of boilers
are condensing or not. When set to On, the boiler
minimum setting is not applied to the lead group
of boilers.
Note: Only available when Fixed Lead / Off DIP
switch is set to Fixed Lead, or when Fixed Last /
Off DIP switch is set to Fixed Last.
ADJUST
ADJUST
ADJUST
ADJUST
ADJUST MENU
OFF, 80 to
180 °F
(OFF, 26.5 to
82.0°C)
Default = 140°F
(60.0°C)
120 to 225°F,
OFF
(49.0 to
107.0°C, OFF)
Default = 200°F
(93.5°C)
Au (Auto), 2 to
42°F
(Au, 1 to
23.5°C)
Default = Au
DMPR
‘Damper’, ALRT
‘Alert’
Default =
DMPR
ADV
ADV
ADV
ADV
BOIL MINIMUM SECTION C
The minimum allowed boiler target temperature
and boiler return protection temperature.
Check the boiler manufacturer’s manual for
recommended supply water temperatures.
BOILER MAXIMUM SECTION C
The maximum boiler target supply temperature
for heat, setpoint and DHW demands. Set
below the high limit setting on the boiler.
BOILER DIFFERENTIAL SECTION C
The temperature differential that the control is
to use to cycle the boiler on and off (half above
and half below target).
RELAY SECTION M
Selects the operation of the relay to be either
combustion air or alert.
PROOF DEMAND SECTION M
Selects the operation of the Proof Demand
to be either off, flow proof, or combustion air
damper.
Note: Only available when Relay is set to
Damper (DMPR).
ADJUST
OFF, Flow
Proof (FP),
Combustion Air
(CA)
Default = OFF
ADV
PUMP PROOF DEMAND DELAY
ADJUST
Primary
min
0:10 to 3:00
minutes
Default = 0:30
ADV
The time allowed for the control to receive a
proof demand once the primary pump turns on.
Note: Only available when Proof Demand is set
to Flow Proof (FP).
CA PROOF DEMAND DELAY
ADJUST
min
Default = 1:00
0:10 to 3:00
minutes
ADV
The time allowed for the control to receive a proof
demand once the Combustion Air (CA) contact
turns on.
Note: Only available when Relay is set to Damper
and Proof Demand is set to Combustion Air (CA).
The time delay for the boiler to operate once
the combustion air damper relay closes.
Note: Only available when Relay is set to Damper
and Proof Demand is set to Combustion Air (CA).
SEQ
(Sequential)
PAR (Parallel)
Default = SEQ
Au (Auto),
0:30 to 40:00
minutes
Default = Au
ADV
ADV
MODULATION MODE SECTION D
Selects either sequential or parallel modulation.
Note: This item is only available when the BTC I
/ Off DIP is set to Off and DHW Mode is set to
1 to 5.
STAGE DELAY SECTION C
The minimum delay between the operation of stages.
Note: This item is only available when at least
two boilers are set to Auto or CP1.
BOILER 1 RELAY SECTION C
(Burner),
(Pump)
1
Default =
ADV
Selects whether the boiler relay is for a burner
or a boiler pump.
Note: This item is only available when Boiler 1
is set to Auto.
BOILER 1 FIRE DELAY SECTION D
min
1
0:00 to 3:00
minutes
Default = 0:10
ADV
Delay from turn-on of ignition (Start Modulation)
until the burner fires.
Note: This item is only available when Boiler 1
is set to Auto.
ADJUST
ADJUST MENU
MIN
1
ADJUST
ADJUST
1
ADJUST
1
min
Default = 0:10
Default = Med
0:00 to 3:00
minutes
Lo, Med, Hi
1 to 1999
Default = 100
1 to 1999
Default = 500
ADV
INST
ADV
ADV
ADV
BOILER 1 MIN SECTION D
MODULATION DELAY
Delay between the burner firing and the boiler
releasing to modulation.
Note: This item is only available when Boiler 1
is set to Auto and Boiler 1 Mode is set to Mod.
BOILER 1 MASS SECTION C
The thermal mass characteristics of the boiler.
Note: This item is only available when Boiler 1
is set to Auto.
BOILER 1 MINIMUM MBH SECTION D
Minimum (low fire) heat output in BTU/hr/1000.
Note: This item is only available when Boiler 1
is set to Auto and Boiler 1 Mode is set to Mod.
BOILER 1 MAXIMUM MBH SECTION D
Maximum (high fire) heat output in BTU/
hr/1000.
Note: This item is only available when Boiler 1
is set to Auto.
The amount of time required for the modulating
actuating motor to fully open the gas valve or operate
the fan speed from a stopped position to full speed.
Note: This item is only available when Boiler 1 is
set to Auto and Boiler 1 Mode is set to Mod.
ADJUST
1
ADJUST
1
ADJUST
1
ADJUST
1
Boiler
ADJUST MENU
BOILER 1 START MODULATION SECTION D
0 to 100%
Default = 0%
ADV
The percent modulation required to obtain
ignition.
Note: This item is only available when Boiler 1
is set to Auto and Boiler 1 Mode is set to Mod.
BOILER 1 MINIMUM SECTION D
0 to 50%
Default = 0%
ADV
MODULATION
The minimum percent modulation of the burner.
Note: This item is only available when Boiler 1 is
set to Auto and Boiler 1 Mode is set to Mod.
BOILER 1 MAXIMUM SECTION D
50 to 100%
Default = 100%
ADV
MODULATION
The maximum percent modulation of the burner.
Note: This item is only available when Boiler 1 is
set to Auto and Boiler 1 Mode is set to Mod.
min
19:55 minutes
Default = 0:20
OFF, 0:10 to
ADV
min
BOILER PUMP 1 PURGE SECTION L
The time the boiler pump remains on once the
boiler is turned off.
Note: This item is only available when Boiler 1
is set to Auto and Boiler 1 relay is set to ‘Pump’.
Note: The previous 11 menu items will repeat for up to four boilers.
ADJUST
AUTO, 5 to 30
minutes
Default = Auto
ADV
The cycle length to which all tN4 devices will
synchronize.
Note: This item is only available when a tN4
device is present.
OFF,
CYCLE LENGTH SECTION R
ADJUST
1 (parallel, no priority)
2 (parallel, priority)
3 (pri-sec, no priority)
4 (pri-sec, priority)
5 (parallel with last
boiler, priority)
6 (dedicated DHW)
ADV
DHW MODE SECTION I
This determines the operation of the primary
pump in combination with the DHW pump and
whether or not DHW priority is required.
Note: This item is only available when the Pump
Sequencer / Off DIP is set to Off.
Default = OFF
DHW SENSOR SECTION I
ADJUST
OFF, ON
Default = OFF
ADV
Selects if a DHW sensor is to be used for
DHW generation.
Note: This item is only available when the
Pump Sequencer / Off DIP is set to Off and
DHW Mode is set to 1, 2, 3 or 4.
The temperature of the DHW tank during the
wake and occupied periods.
Note: This item is only available when DHW
Mode is 1, 2, 3 or 4, the DHW Sensor is set to
On, and the Pump Sequencer / Off DIP is Off.
DHW UNOCCUPIED SECTION I
The temperature of the DHW tank during the
sleep and unoccupied periods.
Note: This item is only available when DHW
Mode is 1, 2, 3 or 4, the DHW Sensor is set to
On, the Pump Sequencer / Off DIP is Off, and
the Setback / Off DIP is set to Setback.
DHW DIFFERENTIAL SECTION I
The temperature differential (swing up and
down) of the DHW tank from the DHW setting.
Note: This item is only available when DHW
Mode = 1, 2, 3, 4 or 6, the DHW Sensor is set to
On, and the Pump Sequencer / Off DIP is Off.
DHW EXCHANGE OCCUPIED SECTION I
The boiler supply temperature to the DHW
heat exchanger during the Occupied and
Wake periods.
Note: This item is only available when DHW
Mode is set to 1, 2, 3, 4 or 5, the DHW Sensor
is set to OFF, and the Pump Sequencer / Off
DIP is set to Off.
DHW EXCHANGE UNOCCUPIED SECTION I
Selects whether the control should respond
to DHW Demands during the Sleep and
Unoccupied periods.
Note: This item is only available when DHW
Mode is set to 1, 2, 3, 4 or 5, the DHW Sensor
is set to OFF, the Pump Sequencer / Off DIP
is set to Off, and the Setback / Off DIP is Off.
DHW BOILER SECTION I
ADJUST
1, 2, 3, 4
Default = 2
ADV
The number of boilers used for indirect DHW
generation.
Note: This item is only available when DHW
Mode = 1, 2, 3, or 4 and the Pump Sequencer
/ Off DIP is set to Off.
SETPOINT MODE SECTION J
Selects the Setpoint mode of operation.
This determines the operation of the
primary pump and whether or not priority is
required.
Note: This item is only available when
DHW Mode is set to Off.
SETPOINT OCCUPIED
SECTION J
The minimum boiler target temperature when
a Setpoint Demand is present during the
Wake and Occupied periods.
Note: This item is only available when
DHW Mode is set to Off.
Selects whether the control should respond to
Setpoint demands while in unoccupied mode.
Note: This item is only available when DHW
Mode is set to Off, and Setback / Off DIP is
set to On.
ZONE LOAD SHEDDING SECTION R
Selects whether Zone Load Shedding is active
or not.
Note: This item is only available when a tN4
device is present and Boiler Minimum is set to
a temperature.
PRIORITY OVERRIDE
SECTION I, J
The amount of time priority is given for DHW or
Setpoint operation before space heating resumes.
Note: This item is only available when DHW
Mode is set to 2, 4, or 5, or Setpoint mode is
set to 2 or 4.
WWSD OCCUPIED SECTION B
The system’s warm weather shut down temperature
during the wake and occupied periods. The
WWSD applies to the space heating loads only.
It does not affect DHW or Setpoint heating loads.
Note: This item is only available when EMS /
Demands DIP is set to Demands.
ADJUST
UnOcc
ADJUST MENU
ADJUST
12
Primary
ADJUST
Primary
ADJUST
35 to 100°F,
(2.0 to 38.0°C,
Default = 60°F
(15.5°C)
12 to 180 hours,
hr
Default = 96
OFF, 0:10 to
min
19:55 minutes
Default = 0:20
OFF, 3 to 40
min
minutes
Default = 20
minutes
OFF
OFF)
OFF
hours
min
ADV
ADV
ADV
ADV
WWSD UNOCCUPIED SECTION B
The system’s warm weather shut down temperature
during the sleep and unoccupied period.
Note: This item is only available when EMS /
Demands DIP is set to Demands and Setback
/ Off DIP is set to Off.
ROTATE PRIMARY PUMPS SECTION L
Select the frequency of rotation of the primary pumps.
Note: This item is only available when Pump
Sequencer DIP is set to Pump Sequencer.
PURGE PRIMARY PUMP SECTION L
Time the primary pump remains on once the
demand is removed to purge heat from the
boiler.
BOILER ALERT SECTION M
Alert signal if boiler supply does not increase
in temperature within the selected time.
Note: This item is only available when
RELAY is set to Alert (ALRT).
After the last item, the control returns to the first item in the menu.
After the last item, the control returns to the first item in the menu.
Schedule Menu (1 of 3)
Description
YEAR
SECTION O
Set the current year.
Note: This item is only available when Daylight Savings
Time is set to Mode 1 or 2.
MODESECTION O
Select whether time should be displayed using a 12
or a 24 hour clock.
Item FieldRange
SCHD
SCHD
SCHEDULE MENU
SCHD
NONE, CTRL,
MST1, MST2,
MST3, MST4,
MBR1, MBR2,
MBR3, MBR4
Default = NONE
24 hr,
5-11, 7dAY
Default = 24 hr
2 (Occ, UnOcc),
4 (Wake, UnOcc,
Occ, Sleep)
Default = 4
Access
USER
INST
ADV
USER
INST
ADV
USER
INST
ADV
The Schedule menu items set the schedule type, the
number of events per day, and the event times.
Description
HEAT SCHEDULE SECTION N
If a schedule is not required, select NONE.
If the schedule is only used by this control, select CTRL.
If the schedule is shared with other tN4 devices, select
MST1 to MST4.
If the schedule is set on another tN4 device, select
MBR1 to MBR4.
Note: This item is only available if the Setback DIP is
set to On and a tN4 device is present.
This item can be viewed in the USER and INST
access levels but can only be adjusted in the ADV
access level.
SCHEDULE TYPE SECTION N
Select the type of schedule.
Note: This item is only available when the Setback /
Off DIP is set to On and the Heat Schedule is set to
Control (CTRL) or Master (MST) 1 to 4.
SCHEDULE MODE SECTION N
Select the number of events per day.
Note: This item is only available when the Setback /
Off DIP is set to On and the Heat Schedule is set to
Control (CTRL) or Master (MST) 1 to 4.
Note: This item is only available when the Setback
/ Off DIP is set to On and the Heat Schedule is set
to Control (CTRL) or Master (MST) 1 to 4 and the
Schedule Type is set to 24 hr.
MONDAY THROUGH FRIDAY SECTION N
Select the times for the scheduled events.
Note: This item is only available when the Setback
/ Off DIP is set to On and the Heat Schedule is set
to Control (CTRL) or Master (MST) 1 to 4 and the
Schedule Type is set to 5-2 or 5-11.
SCHD
Wake UnOccSleep
AM
Wake
UnOccupied
Occupied
Sleep
SCHEDULE MENU
SCHD
Wake UnOccSleep
Wake
UnOccupied
Occupied
Sleep
SCHD
Wake UnOccSleep
Wake
UnOccupied
Occupied
Sleep
AM
AM
– –:– – to 11:50 PM
or
– –:– – to 23:50
Default = 6:00 AM
Default = 8:00 AM
Default = 6:00 PM
Default = 10:00 PM
– –:– – to 11:50 PM
or
– –:– – to 23:50
Default = 6:00 AM
Default = 8:00 AM
Default = 6:00 PM
Default = 10:00 PM
– –:– – to 11:50 PM
or
– –:– – to 23:50
Default = 6:00 AM
Default = 8:00 AM
Default = 6:00 PM
Default = 10:00 PM
USER
INST
ADV
USER
INST
ADV
USER
INST
ADV
SATURDAY AND SUNDAY SECTION N
Select the times for the scheduled events.
Note: This item is only available when the Setback
/ Off DIP is set to On and the Heat Schedule is set
to Control (CTRL) or Master (MST) 1 to 4 and the
Schedule Type is set to 5-2.
SATURDAY SECTION N
Select the times for the scheduled events.
Note: This item is only available when the Setback
/ Off DIP is set to On and the Heat Schedule is set
to Control (CTRL) or Master (MST) 1 to 4 and the
Schedule Type is set to 5-11 or 7 Day.
SUNDAY SECTION N
Select the times for the scheduled events.
Note: This item is only available when the Setback
/ Off DIP is set to On and the Heat Schedule is set
to Control (CTRL) or Master (MST) 1 to 4 and the
Schedule Type is set to 5-11 or 7 Day.
Note: This item is only available when the Setback
/ Off DIP is set to On and the Heat Schedule is set
to Control (CTRL) or Master (MST) 1 to 4 and the
Schedule Type is set to 7 Day.
TUESDAY SECTION N
Select the times for the scheduled events.
Note: This item is only available when the Setback
/ Off DIP is set to On and the Heat Schedule is set
to Control (CTRL) or Master (MST) 1 to 4 and the
Schedule Type is set to 7 Day.
SCHD
Wake UnOccSleep
AM
Wake
UnOccupied
Occupied
Sleep
SCHEDULE MENU
SCHD
Wake UnOccSleep
SCHD
Wake UnOccSleep
AM
Wake
UnOccupied
Occupied
Sleep
AM
Wake
UnOccupied
Occupied
Sleep
– –:– – to 11:50 PM
or
– –:– – to 23:50
Default = 6:00 AM
Default = 8:00 AM
Default = 6:00 PM
Default = 10:00 PM
– –:– – to 11:50 PM
or
– –:– – to 23:50
Default = 6:00 AM
Default = 8:00 AM
Default = 6:00 PM
Default = 10:00 PM
– –:– – to 11:50 PM
or
– –:– – to 23:50
Default = 6:00 AM
Default = 8:00 AM
Default = 6:00 PM
Default = 10:00 PM
USER
INST
ADV
USER
INST
ADV
USER
INST
ADV
WEDNESDAY SECTION N
Select the times for the scheduled events.
Note: This item is only available when the Setback
/ Off DIP is set to On and the Heat Schedule is set
to Control (CTRL) or Master (MST) 1 to 4 and the
Schedule Type is set to 7 Day.
THURSDAY SECTION N
Select the times for the scheduled events.
Note: This item is only available when the Setback
/ Off DIP is set to On and the Heat Schedule is set
to Control (CTRL) or Master (MST) 1 to 4 and the
Schedule Type is set to 7 Day.
FRIDAY SECTION N
Select the times for the scheduled events.
Note: This item is only available when the Setback
/ Off DIP is set to On and the Heat Schedule is set
to Control (CTRL) or Master (MST) 1 to 4 and the
Schedule Type is set to 7 Day.
After the last item, the control returns to the first item in the menu.
The Miscellaneous menu items set display and control
options such as access level and temperature units.
Item FieldRange
MISC
MISC
MISC
MISC MENU
USER,
INST, ADV
Default = INST
°F, °C
Default = °F
1 to 24
Access
USER
INST
ADV
USER
INST
ADV
ADV
Description
ACCESS LEVEL PAGE 4
The access level of the control. The access column
shows which items are visible in each access level.
Note: This item is only available when the Lock /
Unlock DIP switch on the control is set to Unlock
UNITS
Select Fahrenheit or Celsius as the temperature
units.
NUMBER OF DEVICESSECTION R
Number of tN4 devices connected to this tN4 bus.
DEFAULT
MISC
OFF, SEL
ADV
Default = OFF
Press and hold the up and down buttons together
for 1 second to display DEFAULT SEL and load the
default settings. Does not load defaults for items in
the miscellaneous menu.
MISC
275, Software Version
USER
INST
ADV
TYPE
Product number of this control. Hold the Up button
to view the software version.
After the last item, the control returns to the first item in the menu.
The control has a built-in test routine that tests the main
control functions. The control continually monitors the
sensors and displays an error message whenever a fault
is found. The individual outputs and relays are tested using
a test sequence.
Test Sequence
Each step in the test sequence lasts 10 seconds.
Start the test sequence by pressing the Test button.
•
Pause the test sequence by pressing the Test button
•
again. To advance to the next step, press the Test
button again.
If the test sequence is paused for more than five minutes,
•
the control exits the entire test routine.
To advance to a particular step, repeatedly press and
•
release the Test button to display the appropriate device.
HAZARD
Access to the Test button requires the removal of the
front cover and exposes hazardous voltage while the
control is powered. Only trained, qualified and competent
personnel should operate the Test button.
Te s t
Step 1 IF the RELAY item is set to ‘Damper’ or ‘Alert’
the C.A. / Alert relay is closed.
IF the RELAY item is set to ‘Alert’, the C.A. /
Alert relay is opened after 10 seconds
Step 2 The Primary Pump 1 relay is closed.
IF Pump Sequencer DIP is set to On, the Primary
Pump 1 relay is opened after 10 seconds.
IF Pump Sequencer DIP = On
Step 3 The Primary Pump 2 relay is closed.
Press and Hold
for 1 second
IF DHW mode = 1, 2, 5, or 6, the primary pump is
turned off
Step 7 The DHW relay is closed.The C.A. / Alert relay is openedThe primary pump is turned offThe control exits the test sequence.
If a device fails to operate during the test sequence, refer
to the installation section of this brochure to check the
operation of the control. If the control works properly,
refer to any troubleshooting information supplied by the
equipment manufacturer.
Max Heat
The control has a function called Max Heat. As long as
there is a demand for heat the control operates in this mode
for up to 24 hours or until the Test button is pressed. tN4
devices operate to meet their occupied setting +5°F (3°C)
and display the MAX segment to indicate the Max Heat
mode. Use this mode to run the circulators during system
start-up to purge air from the piping.
When a boiler demand is present the control targets Boiler
•
Maximum. If Boiler Minimum = Off, the control then targets
Boiler Design. This allows the Boiler Maximum setting to
be set higher for DHW generation.
When a DHW demand is present the control targets the
•
lower of Boiler Maximum or DHW Exchange.
The Boil Maximum setting and DHW Exchange setting
•
are always available in the Adjust Menu when in Max
Heat. The Boiler Design setting is also available in the
Adjust Menu when in Max Heat and the Boiler Minimum
is set to Off.
DHW priority and WWSD are disabled.
•
To enable Max Heat:
Press and hold the Test button for more than 3 seconds
and less than 6 seconds and the test LED will begin to
flash rapidly. MAX HEAT and TEST are displayed on
screen. No outputs are turned on until there is a demand
for heat present.
IF Boiler 1 = Auto
(repeat for each boiler set to Auto or CP1)
Step 4 Relay 1 is closed for Boiler 1 Pump or Boiler
1 Ignition. Boiler 1 modulates up to the STRT
MOD 1 setting according to the MOTR SPD
1 setting. The boiler is operated for the Fire
Delay 1 time or at least 10 seconds.
IF a demand is present
Step 5 Boiler 1 modulates up to the MAX MOD
1 setting according to the MOTR SPD 1
setting.
Step 6 Boiler 1 modulates down to 0% according
to the MOTR SPD 1 setting, and then Relay
1 is opened.
Press the Test button to cancel Max Heat manually or wait
24 hours and the control will automatically leave the Max
Heat mode.
Zone Test
In Zone Test mode, each tN4 device can be individually
turned on one at a time. The control tests each zone for up
to 5 minutes of no button activity. Use this feature to purge
air out of each zone and assist in troubleshooting. No items
are available in the user interface of the control.
Press and Hold
for 3 seconds
Page 45
To Enable Zone Test:
1. Press and hold the Test button for more than 6 seconds.
The control displays ZONE TEST OFF and the Test LED
remains on.
Te s t
Press and Hold
for 6 seconds
2. Press the Up button to change the display to ZONE
TEST ON. After 3 seconds, the boiler and all pumps
are shut off.
3. The control operates stage one of the tN4 device with
the lowest address number. Device number one (b:01)
has the lowest address number and device 24 (b:24)
has the highest address number. All other tN4 zones
are shut off.
Error Messages (1 of 3)
Error MessageDescription
VIEW
VIEW
VIEW
VIEW
VIEW
VIEW
VIEW
CONTROL ERROR ADJUST
The control failed to read the Adjust Menu settings, and reloaded the factory default settings.
Operation stops until you check all the Adjust Menu settings.
Note: To clear the error, the access level must be set to Advanced and the settings in the
Adjust menu must be checked.
CONTROL ERROR TIME
The control failed to read the Time Menu settings, and reloaded the factory default settings.
Operation continues normally.
Note: To clear the error, the access level must be set to Advanced and the settings in the
Time menu must be checked.
CONTROL ERROR SCHEDULE
The control failed to read the Schedule Menu settings, and reloaded the factory default
settings. Operation continues normally.
Note: To clear the error, the access level must be set to Advanced and the settings in the
Schedule menu must be checked.
CONTROL ERROR MISCELLANEOUS
The control failed to read the Miscellaneous Menu settings, and reloaded the factory default
settings. Operation continues normally.
Note: To clear the error, the access level must be set to Advanced and the settings in the
Miscellaneous menu must be checked.
TN4 BUS ERROR
Communication has been lost on the boiler bus due to a short or open circuit. Check the tN4,
C and R wires for each tN4 device. Check the polarity of the C and R wires. Check for loose
or broken wires. The error message self clears once the error condition is corrected.
To clear the error code, press and hold the up and down buttons together for 5 seconds while
viewing this error message.
DEVICE LOST
Communication is lost to a tekmarNet® device on the boiler bus. The number shown is the
address of the lost device. The LCD on the lost device displays the tekmarNet® communication
symbol and OPEN. Ensure that there is power to the lost device. Trace the wires from the
control to the lost device looking for loose or damaged wires. The error message self clears
when the error condition is corrected.
Note: If you deliberately remove a tekmarNet® device, hold the up and down buttons together
for 5 seconds to clear the error.
MASTER DEVICE ERROR
More than one tN4 System Control has been detected on the tN4 bus. This generally indicates
that two tN4 buses are wired together. Check the tN4 bus wiring. The error message clears
once the error condition is corrected.
4. Pressing the Up button will turn off stage 1, and turn on
stage 2 of the same device (if that device has a second
stage) or turn on stage 1 of the device with the next lowest
address. The Down button can be pressed to move to a
device with a lower address number. The second stage
of a two stage zone is indicated with a small 2 in the
display.
5. The Up and Down buttons can then be used to move
through the devices and the heating stages of each
device on the boiler bus.
To cancel the Zone Test press the Test button. Once the
Zone Test ends or is cancelled, the control resumes normal
operation.
More than one tekmarNet® device has been assigned the same master number.
VIEW
VIEW
VIEW
VIEW
VIEW
BOILER SUPPLY SENSOR SHORT CIRCUIT
Due to a short circuit, the control failed to read the boiler supply sensor. When there is a call
for heat, the control no longer controls the boiler(s). Instead, the control provides a boiler
enable to the boiler’s aquastat or boiler control until the sensor is repaired. The control will not
operate the boiler contact if the Boil Minimum setting is less than 100°F (38.0°C). Locate and
repair the problem as described in the data brochure D 070. The error message self clears
once the error condition is corrected.
BOILER SUPPLY SENSOR OPEN CIRCUIT
Due to an open circuit, the control failed to read the boiler supply sensor. The control no longer
controls the boiler. Instead, the control provides a boiler enable to the boiler’s aquastat or boiler
control until the sensor is repaired. The control will not operate the boiler contact if the Boil
Minimum setting is less than 100°F (38.0°C). Locate and repair the problem as described in the
data brochure D 070. The error message self clears once the error condition is corrected.
Note: If you deliberately remove the boiler supply sensor, power down for 10 seconds then
restart the control.
OUTDOOR SENSOR SHORT CIRCUIT
Due to a short circuit, the control failed to read the outdoor sensor. As a result, the control
assumes an outdoor temperature of 32°F (0.0°C) and continues operation. Locate and repair
the problem as described in the data brochure D 070. The error message self clears once
the error condition is corrected.
OUTDOOR SENSOR OPEN CIRCUIT
Due to an open circuit, the control failed to read the outdoor sensor. As a result, the control
assumes an outdoor temperature of 32°F (0.0°C) and continues operation. Locate and repair
the problem as described in the data brochure D 070. The error message self clears once
the error condition is corrected.
DEVICE SCHEDULE ERROR
The selected system schedule is no longer available. Either the system schedule master is
no longer connected to the network or the system schedule number has been changed on
the schedule master. The error message self clears once the error condition is corrected.
VIEW
DEVICE ERROR AT THERMOSTAT
There is an error on a thermostat or setpoint control that is connected to the 275. Find the
thermostat with this address to locate the source of the error. Once the error on the thermostat
or setpoint control is corrected, this error message will self clear.
VIEW
DHW SHORT CIRCUIT
Due to a short circuit, the control failed to read the DHW sensor. As a result, the control no
longer heats the DHW tank. Locate and repair the problem as described in the data brochure D
070. DHW tank heating will resume once the sensor problem is corrected. The error message
self clears once the error condition is corrected.
VIEW
DHW OPEN CIRCUIT
Due to an open circuit, the control failed to read the DHW sensor. As a result, the control no
longer heats the DHW tank. Locate and repair the problem as described in the data brochure D
070. DHW tank heating will resume once the sensor problem is corrected. The error message
self clears once the error condition is corrected.
Both the primary pump P1 and P2 have failed or the flow proof demand signal was not detected
before the proof demand delay time elapsed.
To clear the error code, press and hold the up and down buttons together for 5 seconds while
viewing this error message.
PRIMARY PUMP P1 FAILURE
The primary pump P1 has failed. The primary pump 1 relay closed, but a flow proof demand
was not detected before the proof demand delay time elapsed.
To clear the error code, press and hold the up and down buttons together for 5 seconds while
viewing this error message.
PRIMARY PUMP P2 FAILURE
The primary pump P2 has failed. The pump 2 relay closed, but a flow proof demand was not
detected before the proof demand delay time elapsed.
To clear the error code, press and hold the up and down buttons together for 5 seconds while
viewing this error message.
PUMP PROOF DEMAND ERROR
The primary pump has been turned off, but the pump proof demand remains after 4
minutes.
To clear the error code, press and hold the up and down buttons together for 5 seconds while
viewing this error message.
COMBUSTION AIR DAMPER FAILURE
The Combustion Air (C.A.) damper has failed. The C.A. relay closed, but the control did not
detect a damper proof demand before the proof demand delay time elapsed.
To clear the error code, press and hold the up and down buttons together for 5 seconds while
viewing this error message.
DAMPER PROOF DEMAND ERROR
The Combustion Air (C.A.) damper has been turned off, but the damper proof demand remains
after 4 minutes.
To clear the error code, press and hold the up and down buttons together for 5 seconds while
viewing this error message.
BOILER RETURN SENSOR SHORT CIRCUIT
Due to an short circuit, the control failed to read the boiler return sensor. The control will
continue to operate normally. Locate and repair the problem as described in the data brochure
D 070. The error message self clears once the error condition is corrected.
VIEW
BOILER RETURN SENSOR OPEN CIRCUIT
Due to an open circuit, the control failed to read the boiler return sensor. The control will
continue to operate normally. Locate and repair the problem as described in the data brochure
D 070. The error message self clears once the error condition is corrected.
VIEW
BOILER ALARM ERROR
The boiler supply temperature did not increase within the boiler alarm time. To reset the
alarm, press and hold the up and down buttons together for 5 seconds while viewing this
error message.
VIEW
DHW ERROR
A DHW sensor and a DHW demand have been applied at the same time. The DHW tank
will not be heated until the DHW Demand signal is removed. The error message self clears
once the condition is corrected.
Boiler Control 275One tN4, Four Modulating Boiler & DHW / Setpoint
Literature275_D, 275_A, D001, D070
ControlMicroprocessor control. This is not a safety (limit) control.
Packaged weight3.3 lbs (1500 g)
Dimensions
EnclosureBlue PVC plastic, NEMA type 1
Approvals
Ambient conditionsIndoor use only, 32 to 122°F (0 to 50°C), RH 90% Non-condensing
Power supply115 V (ac) ±10% 60 Hz, 7 VA, 1150 VA max
Relays230 V (ac) 5 A, 1/3 hp
Modulating output0 - 10 V (dc), Minimum 2500 Ω
Demands20 to 260 V (ac) 2 VA
SensorsNTC thermistor, 10k
- IncludedOutdoor Sensor 070, 2 of Universal Sensors 082, and 500 resistor
WarrantyLimited 3 Year
6-5/8” H x 7-9/16” W x 2-13/16” D (170 x 193 x 72 mm)
CSA C US, meets class B: ICES & FCC Part 15
@ 77°F (25°C ± 0.2°C) ß=3892
Limited Warranty and Product Return Procedure
Limited Warranty The liability of tekmar under this warranty is lim-
ited. The Purchaser, by taking receipt of any tekmar product (“Product”), acknowledges the terms of the Limited Warranty in effect at
the time of such Product sale and acknowledges that it has read
and understands same.
The tekmar Limited Warranty to the Purchaser on the Products sold
hereunder is a manufacturer’s pass-through warranty which the
Purchaser is authorized to pass through to its customers. Under
the Limited Warranty, each tekmar Product is warranted against
defects in workmanship and materials if the Product is installed and
used in compliance with tekmar’s instructions, ordinary wear and
tear excepted. The pass-through warranty period is for a period of
twenty-four (24) months from the production date if the Product is
not installed during that period, or twelve (12) months from the documented date of installation if installed within twenty-four (24) months
from the production date.
The liability of tekmar under the Limited Warranty shall be limited to, at
tekmar’s sole discretion: the cost of parts and labor provided by tekmar
to repair defects in materials and/or workmanship of the defective product; or to the exchange of the defective product for a warranty replacement product; or to the granting of credit limited to the original cost of the
defective product, and such repair, exchange or credit shall be the sole
remedy available from tekmar, and, without limiting the foregoing in any
way, tekmar is not responsible, in contract, tort or strict product liability, for any other losses, costs, expenses, inconveniences, or damages,
whether direct, indirect, special, secondary, incidental or consequential,
arising from ownership or use of the product, or from defects in workmanship or materials, including any liability for fundamental breach of
contract.
The pass-through Limited Warranty applies only to those defective Products returned to tekmar during the warranty period. This Limited Warranty does not cover the cost of the parts or labor to remove or transport
the defective Product, or to reinstall the repaired or replacement Product,
all such costs and expenses being subject to Purchaser’s agreement and
warranty with its customers.
Any representations or warranties about the Products made by Purchaser
to its customers which are different from or in excess of the tekmar Limited Warranty are the Purchaser’s sole responsibility and obligation. Purchaser shall indemnify and hold tekmar harmless from and against any
and all claims, liabilities and damages of any kind or nature which arise
out of or are related to any such representations or warranties by Purchaser to its customers.
The pass-through Limited Warranty does not apply if the returned Product has been damaged by negligence by persons other than tekmar,
accident, fire, Act of God, abuse or misuse; or has been damaged by
modifications, alterations or attachments made subsequent to purchase
which have not been authorized by tekmar; or if the Product was not
installed in compliance with tekmar’s instructions and/or the local codes
and ordinances; or if due to defective installation of the Product; or if the
Product was not used in compliance with tekmar’s instructions.
THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESS
OR IMPLIED, WHICH THE GOVERNING LAW ALLOWS PARTIES TO
CONTRACTUALLY EXCLUDE, INCLUDING, WITHOUT LIMITATION,
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE, DURABILITY OR DESCRIPTION OF THE
PRODUCT, ITS NON-INFRINGEMENT OF ANY RELEVANT PATENTS
OR TRADEMARKS, AND ITS COMPLIANCE WITH OR NON-VIOLATION OF ANY APPLICABLE ENVIRONMENTAL, HEALTH OR SAFETY
LEGISLATION; THE TERM OF ANY OTHER WARRANTY NOT HEREBY
CONTRACTUALLY EXCLUDED IS LIMITED SUCH THAT IT SHALL NOT
EX TEND BEYON D TWE NTY-F OUR (24) MON THS FRO M THE PRODU CTION DATE, TO THE EXTENT THAT SUCH LI MI TATION IS AL LOW ED BY
THE GOVERNING LAW.
Product Warranty Return Procedure All Products that are believed to
have defects in workmanship or materials must be returned, together
with a written description of the defect, to the tekmar Representative
assigned to the territory in which such Product is located. If tekmar
receives an inquiry from someone other than a tekmar Representative,
including an inquiry from Purchaser (if not a tekmar Representative) or
Purchaser’s customers, regarding a potential warranty claim, tekmar’s
sole obligation shall be to provide the address and other contact information regarding the appropriate Representative.
tekmar Control Systems Ltd., A Watts Water Technologies Company.