• Do not touch any electrical switch; do not use any phone
in your building.
• Immediately call your gas supplier from a neighbor's
phone. Follow the gas supplier's instructions.
• If you cannot reach your gas supplier, call your fire
department.
FOR YOUR SAFETY
Do not store or use gasoline or other flammable vapors and
liquids in the vicinity of this or any other appliance.
WARNING: Improper installation, adjustment, alteration,
service, or maintenance can cause property damage, injury,
or death. Read the installation, operation, and maintenance
instructions thoroughly before installing or servicing this
equipment.
WARNING: Gas-fired appliances are not designed for use in
hazardous atmospheres containing flammable vapors or
combustible dust, in atmospheres containing chlorinated or
halogenated hydrocarbons, or in applications with airborne
silicone substances. See Hazard Levels, page 2.
WARNING: Should overheating occur, or the gas supply fail to
shut off, shut off the manual gas valve to the appliance before
shutting off the electrical supply.
WARNING: Do not use this appliance if any part has been under
water. Immediately call a qualified service technician to inspect
the appliance and replace any gas control that has been under
water.
Form RZ-NA I-UDA, Mfg #195673 Rev 9, Page 1
Page 2
Hazard Levels of
W arnings in this
Manual
HAZARD INTENSITY LEVELS
1. DANGER: Failure to comply will result in severe personal injury or
death and/or property damage.
2. WARNING: Failure to comply could result in sever e personal injury or
death and/or property damage.
3. CAUTION: Failure to comply could result in minor personal injury
and/or property damage.
1. General
BOTH this manual and
the correct venting
manual are REQUIRED
for installation of this
heater.
Model UDAP 30, 45, 60, 75, 100, and 125 and Model UDAS 30, 45, 60, 75, 100,
and 125 are design certified by the Canadian Standards Association for use in
residential, industrial, and commercial installations. Unit heaters certified for “residential use” are intended to be used as supplementary heating devices in residential areas such as workshops and garages. They are not intended to be the primary
source of heat in residential applications or to be used in sleeping quarters.
Models UDAP 150, 175, 200, 225, 250, 300, 350, and 400 and UDAS 150, 175,
200, 225, 250, 300, 350, and 400 are design certified by the Canadian Standards
Association for use in industrial and commercial installations only .
All models and sizes are available for use with either natural or propane gas. The
type of gas, the input rate and the electrical supply requirement is shown on the
heater’s rating plate. Check the rating plate to determine if the heater is appropriate for the intended installation.
Installation requires both this manual AND the venting manual.
V enting Manual by Model
Venting InstructionLook for Matching Label on
ModelManual by Form No.Venting Manual and Heater
UDAPStandard Power VentLabel with
Installation (each heaterRed Square
has its own dedicated vent)
- Form RZ-NA I-UD-V-PV
UDAP-CV Optional Common VentLabel with
withInstallation (must beinverted
Optionequipped with Option AV6)Blue Triangle
AV6- Form RZ-NA I-V-CV
Model UDAP-CV is available in Sizes 30, 45, 60, 75, 100 only
UDASSeparated CombustionLabel with
- Form RZ-NA I-UD-V-SCGreen Circle
2. Installation
Codes
Form RZ-NA I-UDA, P/N 195673 Rev 9, Page 2
These units must be installed in accordance with local building codes. In the absence of local codes, in the United States, the unit must be installed in accordance
with the National Fuel Gas Code, ANSI Z223.1. A Canadian installation must be
in accordance with the CSA B149 Installation Codes. These codes are available
from CSA Information Services, 1-800-463-6727. Local authorities having juris-
Both this installation manual and the appropriate venting manual are shipped with
the heater. Verify that the literature is correct for the heater being installed. If
either manual is missing or incorrect, contact your distributor before beginning
installation.
The instructions in this manual apply only to the models listed.
Installation should be done by a qualified agency in accordance with these in-
structions. The qualified service agency installing this heater is responsible for the
installation.
Page 3
diction should be consulted before installation is made to verify local codes and
installation procedure requirements.
Special Installations
(Aircraft Hangars/
Repair Garages/
Parking Garages)
California Warning
Label
Massachusetts
Requirement
3. W arranty
Installations in aircraft hangars should be in accordance with ANSI/NFPA No. 409
(latest edition), Standard for Aircraft Hangars; in public garages in accordance
with ANSI/NFPA No. 88A (latest edition), Standard for Parking Structures; and
for repair garages in accordance with ANSI/NFPA No. 88B (latest edition), Standard for Repair Garages. In Canada, installations in aircraft hangars should be in
accordance with the requirements of the enforcing authorities, and in public garages in accordance with CSA B149 codes.
If the heater is being installed in the state of California, the installer MUST attach
a warning label on the outside of the access door. The California Warning label is
shipped in the owner’s envelope along with this manual, the warranty form, and
any other paperwork that applies.
If installation is in California, select a location on the heater access panel. Be sure
the surface is clean and dry and adhere the label.
If the heater is being installed in the Commonwealth of Massachusetts, these units
must be installed by a licensed plumber or licensed gas fitter .
Refer to the limited warranty information on the Warranty Card in the "Owner's
Envelope".
Warranty is void if ...
a. Wiring is not in accordance with the diagram furnished with the heater.
b. The unit is installed without proper clearance to combustible materials.
c. A fan model is connected to a duct system or if the air delivery system is
modified.
4. Uncrating and
Preparation
This unit was test operated and inspected at the factory prior to crating and was in
operating condition. If the heater has incurred any damage in shipment, document
the damage with the transporting agency and contact an authorized Reznor Distributor. If you are an authorized Distributor, follow the FOB freight policy procedures as published by Thomas & Betts for Reznor products.
Check the rating plate for the gas specifications and electrical characteristics of
the heater to be sure that they are compatible with the gas and electric supplies at
the installation site.
Read this booklet and become familiar with the installation requirements of your
particular heater. If you do not have knowledge of local requirements, check with
the local gas company or any other local agencies who might have requirements
concerning this installation.
Before beginning, make preparations for necessary supplies, tools, and manpower.
If the installation includes optional vertical louvers, downturn nozzle, ceiling mounting bracket, hanger kit, high altitude kit, multiple heater control, and/or stepdown
transformer, install these options before the heater is suspended. Follow the instructions included in the option package; option packages are shipped separately .
Other shipped separate items could include a vent/combustion air kit, high temperature tape, a thermostat bracket kit, a thermostat, and/or a thermostat guard. Be
sure all options ordered are at the installation site.
IMPORTANT: Shipping brackets are attached with cabinet screws. When
removing shipping brackets, re-insert ALL screws into the cabinet.
Form RZ-NA I-UDA, Mfg #195673 Rev 9, Page 3
Page 4
5. Dimensions
M and N - Hanger Dimensions for both 2-pt and 4-pt Suspension
Normal Power Consumption (watts)109155155217276354
Discharge Air Temperature Rise (°F)505560606060
Ai r Vol ume
Discharge Air Opening Area
Output Vel ocity
Fan Motor HP
E
Fan Motor RPM155015501550155010501050
Fan Diameter (inches)101012121616
Sound Leveldba @ 15 ft404040495455
TECHNICAL DATA - Sizes 150 - 400
Size150175200225250300350400
In pu t Heating Capacity
Thermal Efficiency (%)8383838383838383
Output Heating Capacity
Gas C onnection (inches)
Vent Connection
Combustion Ai r Inlet
A
B
C
(inches di a meter )
C
(inche s diameter) Control Amps (24 volt)1.01.01.01.01.01.01.01.0
Full Load Amps (115 volt)3.83.84.67.57.510.710.710.7
Maximum Ov er Current
Protection
D E
Normal Power Consumption (watts)392392491747747108610861086
Discharge Air Temperature Rise (°F)6060606060606060
Ai r Volume
Discharge Air Opening Area
Output Velocity
Fan Motor HP
E
Fan Motor RPM10501050105010501050105010501050
Fan Diameter (inches)1818182020242424
Sound Level dba @ 15 ft5152535656596162
A
CSA ratings for altitudes to 2000 ft.
B
Size shown is for gas connection to a single-stage gas valve, not supply line size.
C
Smaller and/or larger vent and combustion air pipe diameters may be permissible. For Model UDAS refer to the Venting
Installation Manual for Separated Combustion Units. For Model UDAP refer to the Venting Installation Manual for Power
Vented units. For a Model UDAP with Option AV6, refer to the Venting Installation Manual for Common Venting.
D
MOCP = 2.25 x (largest motor FLA) + smallest motor FLA. Answer is rounded to the next lower standard circuit breaker size.
E
Except where indicated, information in this table is based on a heater equipped with a standard 115 volt open fan motor.
Form RZ-NA I-UDA, P/N 195673 Rev 9, Page 6
BTUH30,00045,00060,00075,000105,000120,000
kw8.813.217.622.030.83 5.2
BTUH24,60037,35049,80062,25087,15099,600
kw7.211.014.618.325.62 9.2
Natural1/21/21/21/21/21/2
Pro pane1/21/21/21/21/21/2
444444
UDAS only
444444
Standard 115V151515151515
Optional 208V or 230V151515151515
CFM45662976996113451537
M
3
/minute
2
ft
2
M
12.917.821 .827.536.745.9
0.960.961.251.252.012.01
0.090.090.120.120.190.19
FPM475656616770668763
M/minute145200188238196245
Standard Open0.020.030.030.061/301/20
Optional EnclosedN.A.N.A.N.A.N.A.1/41/4
(Data applies to both Model s UDAP and UDAS unless noted otherwise.)
If the heater is being installed at an elevation above 2000 ft (610M), the input rate
will have to be derated. This is done by adjusting the valve outlet pressure.
Operation
In addition, if the heater is being installed at an altitude above 6000 ft (1830M), the
pressure switch will have to be changed. If ordered with the unit as Option DJ20 or
DJ21, the pressure switch is shipped separately.
Gas valve adjustment for
high altitude can only be
done after heater is
operating; see
Paragraph 12.
Adjusting the valve outlet pressure is done after the heater is in operation; follow
the instructions in Paragraph 12. Capacities and inputs for derated units are also
listed in Paragraph 12.
If the pressure switch needs to be changed, do that before the heater is operated;
follow the instructions in FIGURE 4.
FIGURE 4 - Installing High Altitude Pressure Switch required above 6000 ft (1830M) elevation
Model UDAP
Size30456075100125150 175 200 225 250 300 350 400
High Altitude Switch P/N
Negative Pressure OFF Setpoint "w.c.
Label color
Model UDAP-CV with Option AV6 for Common Venting
Size30456075100
Hig h Altitude Switch P/N197029 197032196388
Negative Pressure OFF Setpoint " w.c.0.600.450.50
Label colorLt BluePinkOrange
Model UDAS
Size30456075100125150 175 200 225 250 300 350 400
Hig h Altitude Switch P/N196388 197030
Dif ferential Pressure OFF Setpoint "w.c.0.500.40
Label c olorOrange Green
197031197032
0.350.45
PurplePink
196362
0.55
White
197029
0.60
Lt. Blue
197031
0.35
Purple
197031
Purple
0.35
201160
1.00
Brown
201160201161
1.001.30
Brown
201161
1.30
White
White
Pressure Switch
8. Clearances
Clearances
Size
30 - 12 5
150 - 4 00
*Suspend t he heater so that the bot t om is a minimum of 5 feet (1 .5 M) above the floor.
Instructions for Changing Pressure Switch
1. In the control compartment, locate the pressure switch.
2. Mark and disconnect the two wires attached to the pressure switch.
3. Disconnect the sensing tube from the pressure switch.
4. Locate the two screws holding the switch mounting bracket. Remove the
screws (save screws) and the pressure switch.
5. Using the same screws, install the high altitude pressure switch. Attach
the sensing tube and wires.
Units must be installed so that the clearances in the table are provided for combustion air space, inspection and service, and for proper spacing from combustible
construction. Clearance to combustibles is defined as the minimum distance from
the heater to a surface or object that is necessary to ensure that a surface temperature of 90°F above the surrounding ambient temperature is not exceeded.
(Note: For Model
UDAS, see V enting
Manual for
combustion air
requirements.)
This heater must be supplied with the air that enters into the combustion process
and is then vented to the outdoors. Sufficient air must enter the equipment location
to replace that exhausted through the heater vent system. In the past, the infiltration of outside air assumed in heat loss calculations (one air change per hour) was
assumed to be sufficient. However , current construction methods using more insulation, vapor barriers, tighter fitting and gasketed doors and windows, weatherstripping, and/or mechanical exhaust fans may now require the introduction of
outside air through wall openings or ducts.
The requirements for combustion and ventilation air depend upon whether the unit
is located in a confined or unconfined space. An "unconfined space" is defined as
a space whose volume is not less than 50 cubic feet per 1000 BTUH of the installed
appliance. Under ALL conditions, enough air must be provided to ensure there
will not be a negative pressure condition within the equipment room or space.
WARNING: Model UDAP and UDAP-CV power-vented unit
heaters are designed to take combustion air from the space in
which the unit is installed and are not designed for connection to
outside combustion air intake ducts. Connecting outside air ducts
voids the warranty and could cause hazardous operation. See
Hazard Levels, page 2.
Combustion Air
Requirements for
a Heater Located
in a Confined
Space - applies to
Model UDAP and
Model UDAP-CV
FIGURE 5 - Definition of
Confined Space and
Required Openings for
Combustion Air
Do not install a unit in a confined space without providing wall openings leading
to and from the space. Provide openings near the floor and ceiling for ventilation
and air for combustion as shown in FIGURE 5, depending on the combustion air
source as noted in Items 1, 2, and 3 below.
Add total BTUH of all appliances in the confined space and divide by figures
below for square inch free area size of each (top and bottom) opening.
Confined Space:
A space whose volume is
less than 50 cubic feet
per 1000 BTUH of the
installed appliance input
rating
1. Air from inside the building -- openings 1 square inch free area per 1000
BTUH. Never less than 100 square inches free area for each opening. See (1) in
FIGURE 5.
2. Air from outside through duct -- openings 1 square inch free area per 2000BTUH. See (2) in FIGURE 5.
3. Air direct from outside -- openings 1 square inch free area per 4000 BTUH.See (3) in FIGURE 5.
(3)
Confined
Space
(3)
(1)
(1)
(2)
(2)
NOTE: For further details on supplying combustion air to a confined space, see
the National Fuel Gas Code ANSI Z223.1a (latest edition).
Form RZ-NA I-UDA, P/N 195673 Rev 9, Page 8
Page 9
10. Unit Heater
g
g
g
g
g
g
g
g
g
g
g
g
g
g
g
g
g
g
g
g
g
g
g
g
g
g
g
g
Location
Use the sound data in Paragraph 6, clearances in Paragraph 8; the combustion air
requirements in Paragraph 9; the throw tables, mounting height requirements, and
location recommendations below; the weights in Paragraph 11; and the venting
requirements in the Venting Manual to determine where to suspend the heater.
Heater Throw
*Louver angle listed in the table is relative to the top of the heater.
FIGURE 6 - Throw for Fan
Models UDAP and UDAS
NOTE: Throws listed are with
standard adjustable horizontal
louvers at the angles listed
(angle is relative to the top of
the heater). Throw pattern
changes with the addition of
optional vertical louvers and/or
downturn nozzles.
Dimensio ns X, Y, and Z (feet ) Mo del UDAP and Mo del U DAS with Standard Horizo nt al Louv ers at Mount ing Heights of 5 - 18 ft
H = Distance from bottom of heater to the floor
X = Distance from heater to start of floor coverage
Y = Distance to end of floor coverage
**Z = point when the air velocity drops below 50 ft (15.2M) per minute
60
XYZ
Louver
XYZ
Louver
XYZ
Louver
XYZ
Louver
75100
le
XYZ
An
le*
XYZ
An
75100125
le
XYZ
An
le*
XYZ
An
le
XY Z
An
Louver
le*
XY Z
Louver
An
le
XY Z
An
Louver
le*
XY Z
Louver
An
250300
le
XY Z
An
Louver
le*
XY Z
Louver
An
le
XY Z
An
Louver
le*
XY Z
Louver
An
le
An
Louver
le*
XYZ
Louver
An
le
An
Louver
le*
XYZ
Louver
An
le*
XYZ
Louver
An
le*
XYZ
Louver
An
400225250300350
le*
Louver
An
le*
Louver
An
Location
Locate the heater so that it is a minimum of five feet (1.5M) above the floor and in
compliance with the clearances in Paragraph 8.
Recommendations
W ARNING: If touched, the vent pipe and internal heater surfaces
that are accessible from outside the heater will cause burns.
Suspend the heater a minimum of 5 feet (1.5M) above the floor.
Form RZ-NA I-UDA, Mfg #195673 Rev 9, Page 9
Page 10
10. Unit Heater
Location
(cont’d)
NOTE: V enting
requirements may
affect location.
Consult the V enting
Manual for this heater
before making final
determination.
For best results, the heater should be placed with certain rules in mind. In general,
a unit should be located from 8 to 12 feet (2.4-3.7M) above the floor . Units should
always be arranged to blow toward or along exposed wall surfaces, if possible.
Where two or more units are installed in the same room, a general scheme of air
circulation should be maintained for best results.
Suspended heaters are most effective when located as close to the working zone as
possible, and this fact should be kept in mind when determining the mounting
heights to be used. However, care should be exercised to avoid directing the discharged air directly on the room occupants.
Partitions, columns, counters, or other obstructions should be taken into consideration when locating the unit heater so that a minimum quantity of airflow will be
deflected by such obstacles.
When units are located in the center of the space to be heated, the air should be
discharged toward the exposed walls. In large areas, units should be located to
discharge air along exposed walls with extra units provided to discharge air in
toward the center of the area.
At those points where infiltration of cold air is excessive, such as at entrance doors
and shipping doors, it is desirable to locate the unit so that it will discharge directly
toward the source of cold air from a distance of 15 to 20 feet (4.6-6.1M).
CAUTION: Do not locate the heater where it may be exposed to
water spray, rain, or dripping water.
Hazards of Chlorine applies to location of
Model UDAS heater
with regard to
combustion air inlet
11. Hanging the
Heater
WARNINGS: Check the
supporting structure to
be used to verify that it
has sufficient load carrying capacity to support
the weight of the unit.
Suspend the heater only
from the threaded nut
retainers or with a manufacturer provided kit.
Do NOT suspend from
the heater cabinet.
Form RZ-NA I-UDA, P/N 195673 Rev 9, Page 10
The presence of chlorine vapors in the combustion air of gas-fired heating equipment presents a potential corrosion hazard. Chlorine found usually in the form of
freon or degreaser vapors, when exposed to flame will precipitate from the compound, and go into solution with any condensation that is present in the heat exchanger or associated parts. The result is hydrochloric acid which readily attacks
all metals including 300 grade stainless steel. Care should be taken to separate
these vapors from the combustion process. This may be done by wise location of
the unit vent and combustion air terminals with regard to exhausters or prevailing
wind directions. Chlorine is heavier than air. Keep these facts in mind when deter mining installation location of the heater in relation to building exhaust systems.
Before suspending the heater, check the supporting structure to be used to verify
that it has sufficient load-carrying capacity to support the weight of the unit.
When the heater is lifted for suspension, support the bottom of the heater with
plywood or other appropriately placed material. If the bottom is not supported,
damage could occur . Before hanging, verify that any screws used for holding shipping brackets were re-installed in the cabinet.
The heater is equipped for either two-point or four-point suspension. A 3/8"-16
threaded nut retainer is located at each suspension point. NOTE: Four-point suspension is required when installing an optional downturn nozzle. See Dimensions
in Paragraph 5 and the illustration in FIGURE 7A.
the Heater with Rods from
the Threaded Nut Retainers
(either two or four point
suspension)
WARNING: Unit must
be level for proper
operation. Do not place
or add additional weight
to the suspended heater.
Hazard Levels, page 2.
FIGURE 7B - Swivel
Connectors to Suspend the
Heater from 1” Pipe, Option
CK8 (2-pt) or CK10 (4-pt)
Be sure the threaded hanger rods are
locked to the heater as illustrated.
Length of threaded rod extending into
the heater MUST NOT exceed 1/2”
(13mm).
Add a 3/8 nut and
washer to lock the
hanger rod to the heater.
3/8 threaded rod
(field supplied)
Recommended maximum hanger
rod length is 6 feet (1.8M).
If ordered with swivel connectors for 1” pipe, Option CK8 or CK10, attach the
swivels at the threaded nut retainers. Suspend with 1” pipe. (See FIGURE 7B.)
Be sure the
threaded swivel
connectors are
locked to the
heater as
illustrated.
Lock the swivel
connector to
the heater.
The connector
is threaded for
hanging from
a 1 pipe.
FIGURE 8 - Suspending the
Heater using Option CK22,
Ceiling Suspension Kit (no
hanger rods)
FIGURE 9 - Model UDAS Plug the unused suspension
points on the control side of
the heater with the 1/2” long
screws and flat washers.
Find the screws and
washers in the literature
bag shipped inside the
heater.
If ordered with a ceiling suspension kit, Option CK22, follow the illustrated instructions in the kit. (See FIGURE 8.)
A vailable for
Sizes 30-125.
Allows the
heater to be
installed one
inch from the
ceiling.
NOR
Model UDAS - Whether using the suspension points or the hanger kit, when installing a Model UDAS, the unused suspension points on the control side of theheater MUST be plugged. Plug these holes with the 1/2” long cap screws and flat
washers shipped in the bag with the heater. (See FIGURE 9.)
Plug any unused suspension points
on the control side with the 1/2long
cap screws and flat washers provide
Control Side
Model UDAS
Form RZ-NA I-UDA, Mfg #195673 Rev 9, Page 11
Page 12
12. Gas Piping
and
Pressures
W ARNING: This appliance is equipped for a maximum gas supply
pressure of 1/2 psi, 3.5 kPa, or 14 inches water column. Supply
pressure gr eater than 1/2 psi requir es installation of an additional
lockup-type service regulator external to the unit.
WARNING: PRESSURE TESTING SUPPLY PIPING
Test Pressures Above 1/2 PSI: Disconnect the heater and manual valve from the
gas supply line which is to be tested. Cap or plug the supply line.
Test Pressures Below 1/2 PSI: Before testing, close the manual valve on the
heater.
Sizing
Gas
Supply
Line
WARNING: All
components of a gas
supply system must be
leak tested prior to
placing equipment in
service. NEVER TEST
FOR LEAKS WITH AN
OPEN FLAME. Failure
to comply could result in
personal injury,
property damage or
death.
Note: When sizing supply lines, consider possibilities of future expansion and increa sed requirements.
Capacity of Piping
Cubic Feet per Hour based on 0.3" w.c. Pressure Drop
Specific Gravity for Nat ural Gas -- 0.6 (Natural Gas -- 1000 BTU/Cubic Ft)
Specific Gravity for Propane Gas -- 1.6 (Propane Gas -- 2550 BTU/Cubic Ft)
Refer to National Fuel G as Code for addit ional information on line sizing.
All piping must be in accordance with requirements outlined in the National Fuel
Gas Code ANSI/Z223.1a (latest edition) or CSA-B149.1 and B149.2 (See Paragraph 2). Gas supply piping installation should conform with good practice and
with local codes. Support gas piping with pipe hangers, metal strapping, or other
suitable material; do not rely on the heater to support the gas pipe.
The heater is orificed for operation with natural gas having a heating value of 1000
(± 50) BTUH per cubic ft or propane gas with a heating value of 2500 (± 100)
BTUH per cubic ft. If the gas at the installation does not meet these specifications,
consult the factory for proper orificing.
Pipe joint compounds (pipe dope) shall be resistant to the action of liquefied petroleum gas or any other chemical constituents of the gas being supplied.
Install a ground joint union and manual shutoff valve upstream of the unit control
system, as shown in FIGURE 10. Installation of a trap with a minimum 3" (76mm)
drip leg is required.
The unit is equipped with a nipple that extends outside the cabinet. The gas connection is either 1/2” or 3/4”.
Gas Connection Size
Form RZ-NA I-UDA, P/N 195673 Rev 9, Page 12
Ga s Connection (inches)
Size30456075 100 125 150 175 200 225 250 300 350 400
Leak-test all connections by brushing on a leak-detecting solution.
FIGURE 10 - Gas
connection is at the pipe
nipple that extends outside
the cabinet
Illustration shows both a
vertical and horizontal gas
supply; requirements are
the same.
Valve Outlet or Orifice
Pressure Setting
NOTE: Gas Conversion
Kits are available for
changing from propane gas
to natural gas or natural gas
to propane gas. A factoryauthorized conversion kit
MUST be used.
Ground
Joint Union
To Gas Valve
(inside the
cabinet)
Pipe nipple extending
outside the cabinet.
To Gas Valve
(inside the
cabinet)
Measuring valve outlet gas pressure cannot be done until the heater is in operation.
It is included in the steps of the "Check-T est-Start" procedure in Paragraph 24. The
following warnings and instructions apply .
Manual shutoff
Drip
Leg
Ground
Joint
Union
From Gas Supply
(horizontal or vertical)
Manual shutoff
Drip
Leg
W ARNING: V alve outlet gas pr essure must never exceed 3.5" w .c.
for natural gas and 10" w.c. for propane gas.
For Natural Gas: When the heater leaves the factory , the combination gas valve is
set so that the valve outlet gas pressure for a single stage valve or high fire of a two
stage valve is regulated to 3.5" w.c. Inlet supply pressure to the valve for natural
gas must be a minimum of 5" w .c. or as noted on the rating plate and a maximum of
14" w .c.
For Propane Gas: When the heater leaves the factory, the combination gas valve
is set so that the valve outlet gas pressure for a single stage valve or high fire of a
two stage valve is regulated to 10" w.c. Inlet supply pressure to the valve for propane gas must be a minimum of 11" w.c. and a maximum of 14" w.c.
Before attempting to measure or adjust valve outlet gas pressure, the inlet supply
pressure must be within the specified range both when the heater is in operation and
on standby . Incorrect inlet pressure could cause excessive valve outlet gas pressure
immediately or at some future time. If natural gas supply pressure is too high,
install a regulator in the supply line before it reaches the heater. If natural gas supply pressure is too low, contact your gas supplier.
Check V alve Outlet
Pressure (can only be
done after heater is
operating)
NOTE: If operating at high
altitude, outlet pressure
requires adjustment. Follow
instructions on page 14.
Instructions
1) Locate the 1/8” output pressure tap on the valve (See FIGURE 11, page 14).
With the manual valve turned off to prevent flow to the gas valve, connect a
manometer to the 1/8" pipe outlet pressure tap in the valve. NOTE: A manometer
(fluid-filled gauge) is recommended rather than a spring type gauge due to the
difficulty of maintaining calibration of a spring type gauge.
2) Open the manual valve and operate the heater. (NOTE: On Model UDAS, de-
press and hold the door safety switch.) Measure the outlet pressure of the gas
valve. Normally when operating at sea level, adjustments should not be necessary to the factory setting. (For high altitude settings, see next paragraph.)
If adjustment is necessary, remove the cap from the adjustment screw(s). Set
pressure to correct settings by turning the regulator screw IN (clockwise) to
increase pressure. Turn regulator screw OUT (counterclockwise) to decrease
pressure.
Form RZ-NA I-UDA, Mfg #195673 Rev 9, Page 13
Page 14
12. Gas Piping
Instructions for High Altitude Derate
1. Determine the required valve outlet pressure for the elevation where the heater
and
Pressures
Valve Outlet Pressure Settings by Elevation
(cont’d)
Derate by V alve
Outlet Pressure
Adjustment for High
Altitude Operation
This adjustment can only
be done after the heater is
in operation. It is included
in the startup procedures.
NOTE: If elevation is
above 6000 ft (1830M), a
high altitude pressure
switch is required; see
Paragraph 7.
FIGURE 11 - Top View of
Valves showing Outlet
Pressure Tap and
Adjustment Locations
Single-Stage Valve
Output
Adjustment
Screw
Inlet
Pressure
Tap
1/8” Output
Pressure Tap
Two -Stage Valve
Adjust High
Pressure
Output
Inlet
Pressure
Tap
Form RZ-NA I-UDA, P/N 195673 Rev 9, Page 14
Adjust Low
Pressure
Output
1/8” Output
Pressure
Tap
2. Locate the 1/8” output pressure tap on the valve (See FIGURE 11). Turn the
3. Single Stage and Two Stage High Fire - Turn the knob on the top of the valve
4. Turn up the thermostat. (NOTE: On Model UDAS, depress and hold the door
5. With the heater operating determine that the inlet pressure to the heater for
6. Find the High Altitude Adjustment label in the plastic bag that contained these
will be operating. If unsure of the elevation, contact the local gas supplier.
Manifold Pressure Settings by Altitude for the UNI T ED STATE S
Alt itudeNatural Gas (inches w.c.)Propane Gas (inches w.c.)
knob on the top of the valve to “OFF”. Connect a manometer to the 1/8" pipe
outlet pressure tap in the valve. Use a water column manometer that is readable
to the nearest tenth of an inch.
to “ON”. Remove the cap from the pressure adjusting screw and adjust the gas
train pressure to the pressure selected from the table above. Adjust pressure by
turning the regulator screw IN (clockwise) to increase pressure or OUT (counterclockwise) to decrease pressure.
Two Stage Low Fire - Disconnect the wire from the “HI” terminal on the gas
valve and check the low fire pressure. Turn the regulator screw to adjust the low
fire outlet pressure to the “Low Fire” pressure selected from the table. Re-connect the wire to the gas valve.
safety switch.) Cycle the burner once or twice to properly seat the adjustment
spring in the valve.
Re-check the pressure(s). When the outlet pressure is right for the installation,
remove the manometer and replace the cap.
Check for leak at the pressure tap fitting.
natural gas is between 5 and 13.5 inches w.c. and for propane between 10 and
13.5 inches w .c. Take this reading as close as possible to the heater (Heaters are
equipped with gas valves that have an inlet pressure tap.) If the inlet pressure is
not within the specified range, the inlet pressure must be corrected and Steps 3
and 4 repeated.
instructions. Using a permanent marker, fill-in the appropriate information from
the tables on page 15. Select a location for the label on the outside of the heater
access panel so that it will be conspicuous to anyone operating or servicing the
unit. Be sure the surface is clean and dry and adhere the label.
Page 15
High Altitude
Capacity Changes
The input and/or the capacity of the heater changes with the derate. The tables
below list inputs and capacities at altitudes from sea level to 10,000 ft (3045M).
BTUH Inputs and Capacities by Altitud e in the UNITE D STATES for Mod el UDAP and Model UDAS
6,889,686) designed to provide controlled flame stability without lifting or flashback
with either natural or propane gas.
The burner can be removed as a unit for inspection or service; see Maintenance
Section for removal instructions.
14. Electrical
Supply and
Connections
CAUTION: Route wires
so that they do not
contact the flue wrapper
or venter housing.
CAUTION: If any of the
original wire as supplied
with the appliance must
be replaced, it must be
replaced with wiring
material having a
temperature rating of at
least 105°C, except for
limit control, flame
rollout, and sensor lead
wires which must be
150°C. See Hazard
Levels, page 2.
All electrical wiring and connections, including electrical grounding MUST be made
in accordance with the National Electric Code ANSI/NFPA No. 70 (latest edition)
or, in Canada, with CSA Standard C22.1. In addition, the installer should be aware
of any local ordinances or gas company requirements that might apply.
Check the rating plate on the heater for the supply voltage and current requirements. A dedicated line voltage supply with disconnect switch should be run directly from the main electrical panel to the heater. All external wiring must be
.
within approved conduit and have a minimum temperature rise rating of 60°C
Conduit must be run so as not to interfere with the heater access panel. If the installation
requires a stepdown transformer (Option CG), follow the instructions shipped with
the option package for attaching the transformer to the heater.
The electrical supply enters at the rear of the heater (See FIGURE 13). Model
UDAS includes a built-in disconnect switch (20A @ 115V; 10A @ 230V Rating).
Model UDAS supply wiring connects to leads located inside a sealed electrical
box. To maintain the sealing feature of the electrical box, always replace the cover
plate. Model UDAP supply wiring connects directly to leads on the integrated cir cuit board.
The circuit board (See FIGURE 12) is located inside on the bottom of the control
compartment. The circuit board is polarity sensitive. It is advisable to check the
electrical supply to be certain that the black wire is the “hot” wire and that the white
wire is the neutral wire. The supply connection made to “L1” on the circuit board
must be the “hot” wire.
x
Spark
Transformer
Plug
Control
Fuse
FIGURE 12 - Supply
Wiring Connections at
the Circuit Board (DSI
Integrated Control
Module)
Connections
NOTE: Circuit board is polarity sensitive; “hot” wire MUST BE
connected to Terminal L1.
24V Control Wiring
Connections
Form RZ-NA I-UDA, P/N 195673 Rev 9, Page 16
For all models, the terminal strip for 24 volt thermostat connections is located on
the outside of the cabinet at the back of the heater (See FIGURE 13). Wires from
the terminal strip are factory wired to the circuit board.
Supply
Wiring
Thermostat
Connections
Fan/Blower
Status
Lights
Off
Delay
Page 17
15. Thermostat
and
Connections
Use either an optional thermostat available with the heater or a field-supplied 24volt thermostat. Install according to the thermostat manufacturer's instructions, paying particular attention to the requirements regarding the location of the thermostat.
Make sure that the heat anticipator setting on the thermostat is 0.6 amps (or in
accordance with the amperage value noted on the wiring diagram of your heater).
Make thermostat connections at the terminal strip on the back of the heater. The
strip has four terminals, R, G, W1, and W2; refer to the wiring diagram.
IMPORTANT:All units MUST be operated by a 24-volt thermostat. Never use
a line voltage disconnect switch as a means of operating the heater . Operating Model
Sizes 30-125 by means other than a 24-volt thermostat may result in the flame
rollout switch tripping.
FIGURE 13 - Terminal Strip for 24-volt wiring is on the outside rear of the heater
NOTE: The size of heater illustrated has a vertical terminal strip. Some sizes have a horizontal terminal strip.
Rear View - Model UDAP
Terminal
Strip
Supply
Wiring
Entrance
Unit Mounted
Thermostat Option CM3
Rear View - Model UDAS
Terminal
R
G
W1
W2
Disconnect
If the heater was ordered with Option CM3, a kit for mounting the thermostat on
the rear of the heater is shipped separately. Follow the instructions in the option
package to attach the bracket.
Select a snap-action thermostat when using the unit mounted thermostat bracket.
Do not use a mercury switch thermostat because the vibration may cause excessive
unit cycling. Be careful with the thermostat leads; shorting the thermostat wires to
a metal surface will cause the transformer to fail.
Strip
Built-in
Switch
Supply
Wiring
Entrance
R
G
W1
W2
Multiple Heater
Control - Option
CL31 and Option
CL32
If the heater was ordered with a multiple heater control option, one thermostat can
be used to control up to six heaters. The option includes a 40VA transformer that
replaces the standard transformer in the “master” unit and a relay assembly that
attaches to the “slave” unit. Option CL31 provides for control of two heaters. If
control of additional heaters is desired (up to six total), Option CL32 which is the
relay assembly only must be added to each of the “slave” heaters.
The option packages are shipped separately and include complete instructions on
installation and wiring.
Form RZ-NA I-UDA, Mfg #195673 Rev 9, Page 17
Page 18
16. Combustion
Air Proving
Switch
(Pressure
Switch)
DANGER: Safe
operation of this unit
requires proper venting
flow. NEVER bypass
combustion air proving
switch or attempt to
operate the unit without
the venter running and
the proper flow in the
vent system. Hazardous
conditions could result.
See Hazard Intensity
Levels, page 2.
The combustion air proving switch is a pressure sensitive switch that monitors air
pressure to ensure that proper combustion airflow is available. On Model UDAP,
the switch is a single pole/normally open device which closes when a negative
pressure is sensed in the venter housing. On Model UDAS, the switch senses the
differential pressure between the negative pressure in the venter housing and the
pressure in the cabinet. (For switch location, see FIGURE 18, page 31.)
On startup when the heater is cold, the sensing pressure is at the most negative
level, and as the heater and flue system warm up, the sensing pressure becomes
less negative. After the system has reached equilibrium (about 20 minutes), the
sensing pressure levels off.
If a restriction or excessive flue length or turns cause the sensing pressure to be
outside the switch setpoint, the pressure switch will function to shutoff the main
burner. The main burner will remain off until the system has cooled and/or the flue
system resistance is reduced.
The two T ables on the left below list the approximate water column negative pressure readings and switch setpoints for sea level operating conditions for Model
UDAP and Model UDAP-CV heaters. The Table on the right lists the approximate
water column differential pressure readings and switch setpoints for sea level operating conditions for Model UDAS heaters.
All units are equipped with a temperature activated auto reset limit control. The
Label
Color
Switch
P/N
Label
Color
Model
U DAS
Switch
P/N
197028
196388
197029
197029
196362
Differential Pressure Measured in " w.c.
control is factory set and is non-adjustable. If the setpoint is reached, the limit
control will interrupt the electric supply to the gas valve. This safety device provides protection in the case of motor failure or lack of airflow due to a restriction at
the inlet or outlet. (For location, see FIGURE 18, page 31.)
Label
Color
Switch
P/N
CAUTION: The auto reset limit contr ol will continue to shut down
the heater until the cause is corrected. Never bypass the limit
control; hazardous conditions could result. See Hazard Intensity
Levels, page 2.
Form RZ-NA I-UDA, P/N 195673 Rev 9, Page 18
Page 19
18. Flame
Rollout
Switch Sizes 30-125
only
Sizes 30-125 are equipped with a temperature activated manually reset flame rollout
switch. The flame rollout switch is located at the top of the burner assembly. It is
factory set and is non-adjustable. If the setpoint is reached, the flame rollout acts to
interrupt the electric supply to the gas valve. If the flame rollout switch activates,
identify and correct the cause before resetting the switch. Refer to the Maintenance Section for information on probable causes and instructions on resetting the
flame rollout switch. (For location, see FIGURE 18, page 31.)
DANGER: If the manual reset flame rollout switch activates,
identify and correct the cause before resetting the switch. Never
bypass the flame rollout switch; hazardous conditions could result.
See Hazard Intensity Levels, page 2.
19. Door Switch
- Model
UDAS only
20. Ignition
System
FIGURE 14 – DSI Integrated Control Module (circuit board)
x
Spark
Transformer
Plug
Control
All sizes of Model UDAS heaters are equipped with a door switch which prevents
the heater from operating when the service door panel is open. The service panel
of a Model UDAS is equipped with a pliable gasket material that fully seals the
door to provide added protection from building air entering the combustion zone
of the heater. (For switch location, see FIGURE 18, page 31.)
This heater is equipped with a direct spark integrated control module (circuit board).
The module monitors the safety devices and controls the operation of the fan and
venter motors and the gas valve between heat cycles.
Fuse
Thermostat
Connections
Fan/Blower
Off
Delay
LED lights are visible through
viewport on Model UDAS.
Remove door panel to view LED
lights on Model UDAP.
Dip Switch
Status
Lights
Control Status - Green LED Codes
Steady ON....... Normal Operation, No call for heat
Fast Flash........ Normal Operation, Call for heat
1 Flash ............ System Lockout, Failed to detect or sustain
flame
2 Flashes ......... Pressure Switch Did Not Close within 30
Seconds of Venter Motor
3 Flashes ......... High Limit or Flame Rollout Switch Open
4 Flashes ......... Pressure switch is closed before venter
motor is energized
Steady OFF ..... Blown Fuse, No Power, or Defective Board
LED lights are visible
through viewport on Model
UDAS. Remove door panel
to view LED lights on Model
UDAP.
1) Call for Heat - The thermostat calls for heat by energizing the “W” terminal.
The control checks to see that the limit switch is closed and the pressure switch is
open. If the limit switch is open, the control responds as defined in the “Abnormal
Heat Cycle, Limit Switch Operation”. If the pressure switch is closed, the control
will do four flashes on the green LED and wait indefinitely for the pressure switch
to open. If the pressure switch is open, the control proceeds to prepurge.
2) Prepurge - The control energizes the venter motor and waits for the pressure
switch to close. If the pressure switch does not close within 30 seconds of the
venter motor energizing, the control will do two flashes on the green LED. The
control will leave the venter motor energized indefinitely as long as the call for
heat remains and the pressure switch is open.
When the pressure switch is proven closed, the control begins the prepurge time.
If flame is present any time while in prepurge, the prepurge time is restarted. If
flame is present long enough to cause lockout, the control responds as defined in
“Fault Modes, Undesired Flame”.
The control runs the venter motor for a 20 second prepurge time, then proceeds to
the ignition trial period.
3) Ignition Trial Period - The control energizes the spark and main gas valve.
The venter remains energized. If flame is sensed during the first 16 seconds, the
spark is de-energized and the control proceeds to heat fan/blower on delay. If
flame has not been sensed during the first 16 seconds, the control de-energizes the
spark output and keeps the gas valve energized for an additional one second flame
proving period. If flame is not present after the flame proving period, the control
de-energizes the gas valve and proceeds with ignition re-tries as specified in “Abnormal Heat Cycle, Ignition Re-try”. If flame is present, the control proceeds to
the fan/blower on delay.
4) Fan/Blower On Delay - The control waits for 30 seconds from the time the gas
valve opened and then energizes the fan/blower motor. The gas valve and venter
motor remain energized. The control proceeds to steady heat mode.
5) Steady Heat - Control inputs are continuously monitored to ensure limit and
pressure switches are closed, flame is established, and the thermostat call for heat
remains. When the thermostat call for heat is removed, the control de-energizes
the gas valve and begins post-purge and fan/blower off delay timing.
6) Post Purge - The venter motor output remains on for a 45 second post-purge
period after the thermostat is satisfied.
7) Fan/Blower Off Delay - The fan/blower motor is de-energized after a blower
off delay as selected by the dip switches. Timing begins when the thermostat is
satisfied. Delay times are as follows:
Interrupted Thermostat Call for Heat - If the thermostat demand for heat is
removed before the flame is recognized, the control will run the venter motor for
the post purge period and de-energize all outputs.
If the thermostat demand for heat is removed after successful ignition, the control
will de-energize the gas valve, run the venter motor through post purge, and run
the fan/blower motor on heat speed for the selected delay off time.
Page 21
Ignition Retry - If flame is not established on the first trial for ignition period, the
control de-energizes the gas valve and the venter motor remains energized for an
inter-purge period of 10 seconds. The spark and gas valve are then re-energized,
and the control initiates another trial for ignition.
If flame is not established on the second trial for ignition, the control de-energizes
the gas valve, energizes the fan/blower motor on heat speed, and venter motor
remains energized. The fan/blower motor is shut off after the longest selectable
fan delay time (180 seconds). When the fan/blower motor de-energizes, the spark
and gas valve are re-energized and the control initiates another trial for ignition.
(This fan delay is self-healing feature for an open auxiliary limit switch).
If flame is not established on the third trial for ignition period, the control deenergizes the gas valve, and the venter motor remains energized for an inter-purge
period of 10 seconds. The control then re-energizes the gas valve and spark and
initiates another trial for ignition.
If flame is not established on the fourth trial for ignition (initial try plus 3 re-tries),
the control de-energizes the gas valve and goes into lockout. The control goes to
one flash on the green LED to indicate ignition failure lockout.
Limit Switch Operation - The limit switch is ignored unless a call for heat is
present (W energized). If the limit switch is open and a call for heat is present, the
control de-energizes the gas valve and turns the fan/blower motor on heat speed
and runs the venter motor.
When the switch re-closes or the call for heat is lost, the control runs the venter
motor through post purge and runs the blower/fan motor through the selected fan
off delay. The control will return to normal operation after fan off delay is completed.
Pressure Switch - If the pressure switch opens before the trial for ignition period,
the venter motor will run through the pressure switch recognition delay (2 seconds), the gas valve will be de-energized, and the venter motor will run through
the postpurge time. The control will re-start the heat cycle at the pressure switch
proving state if the call for heat still exists.
Pressure switch opening for less than 2 seconds during the trial for ignition period
shall not interrupt the heat cycle. (Gas valve will de-energize while the pressure
switch is open.)
If the pressure switch opens after a successful ignition, the control will de-energize
the gas valve. If flame is lost before the end of the 2 second pressure switch recognition delay, the control will respond to the loss of flame. If the pressure switch
remains open for 2 seconds and the flame remains, the control de-energizes the gas
valve, the venter motor runs through post-purge, and the fan/blower motor runs on
heat speed through the selected fan off delay. When the fan off delay is over, the
fan/blower motor is de-energized, and a heat cycle is begun if the call for heat still
exists.
Continuous Fan
Operation
When the thermostat calls for continuous fan (G) without a call for heat, the fan
motor is energized after a .25 second delay . NOTE: This brief on delay is to allow
the “G” terminal to energize slightly before “Y” and an external changeover relay
to switch from “G” to “W” without causing momentary glitches in the fan/blower
output. The fan remains energized as long as the call for fan remains without a call
for heat.
If a call for heat (W) occurs during continuous fan, the fan/blower will de-energize.
A call for fan is ignored while in lockout.
Form RZ-NA I-UDA, Mfg #195673 Rev 9, Page 21
Page 22
20. Ignition
System
(cont’d)
Fault Modes
Undesired Flame - If flame is sensed longer than 20 seconds while the gas valve
is de-energized, the control shall energize the venter motor and fan/blower motor
on heat speed. When flame is no longer sensed, the venter motor will run through
postpurge, and the fan/blower motor will run through the selected heat fan off
delay time. The control will do a soft lockout, but will still respond to open limit
and flame. The FLAME (yellow) LED shall flash rapidly when lockout is due to
undesired flame.
Gas Valve Relay Fault - If the control senses the gas valve as energized for more
than one second when the control is not attempting to energize the gas valve, or the
gas valve is sensed as not energized when it is supposed to be energized, then the
control will lockout with green LED off. The control assumes either the contacts of
the relay driving the gas valve have welded shut, or the sensing circuit has failed.
The venter motor is forced off to open the pressure switch to stop gas flow unless
flame is present.
If the gas valve was sensed as closed when it should be open, and has not deenergized after the venter motor was shutoff for 15 seconds, then the venter motor
is re-energized to vent the unburned gas.
Lockout
21. Gas V alve
Soft Lockout - The control shall not initiate a call for heat or call for continuous
fan while in lockout. The control will still respond to an open limit and undesired
flame. Lockout shall automatically reset after one hour. Lockout may be manually
reset by removing power from the control for more than one second or removing
the thermostat call for heat for more than one and less than 20 seconds.
Hard Lockout - If the control detects a fault on the control board, the status LED
will be de-energized, and the control will lockout as long as the fault remains. A
hard lockout will automatically reset if the hardware fault clears.
Power Interruption - During a momentary power interruption or at voltage levels
below the minimum operating voltage (line voltage or low voltage) the system will
self-recover without lockout when voltage returns to the operating range.
Power interruptions of less than 80mS shall not cause the control to change operating states. Power interruptions greater than 80mS may cause the control to interrupt the current operating cycle and re-start.
The main operating gas valve is powered by the 24-volt control circuit through the
thermostat and safety controls. The main control valve is of the diaphragm type
providing regulated gas flow preset at the factory . (For location, see FIGURE 18,
page 31.)
WARNING: The operating valve is the prime safety shutoff. All
gas supply lines must be free of dirt or scale before connecting
the unit to ensure positive closure. See Hazard Levels, page 2.
22. Fan Motor
Form RZ-NA I-UDA, P/N 195673 Rev 9, Page 22
The fan motor is equipped with thermal overload protection of the automatic reset
type. Should the motor refuse to run, it may be because of improper current characteristics. Make certain that the correct voltage is available at the motor.
NOTE: If the unit is equipped with an optional totally enclosed motor or optional
voltage, the horsepower may be larger than the standard motor . Refer to the motor
nameplate to verify horsepower.
Page 23
23. Wiring Diagrams
FIGURE 15A - Typical Wiring Diagram for Model UDAP or Model UDAS, Single Stage
(OPT CL3) T874F OR (OPT CL1) W.R.
(OPT CL2) W.R. 1C30-341 THERMOSTAT
1C30-341 THERMOSTAT (SEE NOTE #8)
W-S23-6 SUBBASE (SEE NOTE #8)
SYSTEM TRANSFORMER
R
24V
BR
SW1
FUSE
3.0 AMP
ATO OR ATC
LED FLASH CODES
GREEN LED
NORMAL OPERATION NO CALL FOR HEATSTEADY ON
FAST FLASH
1 FLASH
2 FLASH
3 FLASH
4 FLASH
STEADY OFF
SLOW FLASH WEAK FLAME
NORMAL OPERATION CALL FOR HEAT
IN LOCKOUT FROM FAILED IGNITIONS OR FLAME LOSSES
PRESSURE SWITCH DOES NOT CLOSE WITHIN 30 SECONDS
OF VENTER ENERGIZED
LIMIT SWITCH OR ROLLOUT SWITCH OPEN
PRESSURE SWITCH IS CLOSED BEFORE VENTER IS
ENERGIZED
INTERNAL CONTROL FAULT OR NO POWER
YELLOW LED
FLAME SENSEDSTEADY ON
UNDESIRED FLAME (VALVE OPEN & NO CALL FOR HEAT)FAST FLASH
Y
LA
E
FF D
O
N
A
F
S W 1
E
TIM
1
2
FF
O
FF
O
N
O
N
O
DSI CONTROL
N
O
FF
O
FF
O
N
O
90
120
160
180
Y
VOLT
115/208/230
BK
L1NEUTRAL NEUTRAL L1COMSEC
LED
TEST
OKFLAME
LED
GY
Y
Y
BL
BR
R
BR
FACTORY WIRING
FIELD WIRING
OPTIONAL FACTORY
WIRING
WIRE NUT
P3-1
P3-2
P3-3
P3-4
R
P3-5
P1-8
P1-3
P1-6
P1-5
P1-4
P1-2
P1-7
P1-9
Y
G
W
R
C
W
R
TERMINAL STRIP
G
G
W1
W
R
R
W2
PR
Y
DOOR INTERLOCK
(UDAS ONLY)
R
LIMIT CONTROL
RR
RR
FLAME ROLLOUT
(MODELS 30-125 ONLY)
PRESSURE SWITCH
Y
GAS VALVE
BL
FLAME
ELECTRODE
FLAME
GROUND
LINE/1/60
W
(UDAS ONLY)
DISCONNECT SWITCH
BKBK
NEUTRAL
EAC/BLO
IND
NEUTRAL
SPARK
TRANSFORMER
W
BK
BK
W
G
GRD
SCREW
FAN MOTOR
BK
BR
CAPACITOR
(SEE NOTE #6)
W
(SEE NOTE #7)
SPARK GAP
G
G
W
G
BR/W
VENTER
MOTOR
BR/W
CAPACITOR
BK
G
BR
1. SET THERMOSTAT AT LOWEST SETTING, (FAN SWITCH
AT "AUTO" POSITION, OPTION CL2 ONLY).
2. TURN ON MANUAL GAS VALVE.
3. TURN ON POWER TO UNIT.
4. SET THERMOSTAT AT DESIRED SETTING.
5. THERMOSTAT CALLS FOR HEAT, ENERGIZING THE VENTER MOTOR.
6. VENTER PRESSURE SWITCH CLOSES, FIRING UNIT AT FULL RATE.
7. BURNER FLAME IS SENSED, AND IN 30 SECONDS THE FAN
8. IF THE FLAME IS EXTINGUISHED DURING MAIN BURNER OPERATION,
THE INTEGRATED CONTROL SYSTEM CLOSES THE MAIN VALVE AND
MUST BE RESET BY INTERRUPTING POWER TO THE CONTROL CIRCUIT
(SEE LIGHTING INSTRUCTIONS).
9. SET FAN SWITCH AT "ON" POSITION FOR CONTINUOUS FAN OPERATION, OPTION CL2 ONLY.
1. THE FOLLOWING CONTROLS ARE FIELD INSTALLED OPTIONS: THERMOSTAT
2. DOTTED WIRING INSTALLED BY OTHERS.
3. CAUTION: IF ANY OF THE ORIGINAL WIRING AS SUPPLIED WITH THE
APPLIANCE MUST BE REPLACED, IT MUST BE REPLACED WITH WIRING MATERIAL
HAVING A TEMPERATURE RATING OF AT LEAST 105° C. EXCEPT FOR SENSOR
LEAD WIRE, FLAME ROLLOUT AND LIMIT WIRING WHICH MUST BE 150° C.
4. USE 18 GA. WIRE FOR ALL WIRING ON THE UNIT.
5. LINE AND FAN MOTOR BRANCH WIRE SIZES SHOULD BE OF A SIZE TO PREVENT
VOLTAGE DROPS BEYOND 5% OF SUPPLY LINE VOLTAGE.
6. CAPACITOR IS REMOTE MOUNTED AND INCLUDED ONLY ON 115V MODELS
150-400 AND 208/230V MODELS 100-400.
7. CAPACITOR IS REMOTE MOUNTED AND INCLUDED ONLY ON MODELS 150 - 400.
8. SET THERMOSTAT ANTICIPATOR AT 0.6 AMPS.
OPERATING SEQUENCE
MOTOR IS ENERGIZED.
NOTES
FIELD CONTROL WIRING
TOTAL WIRE
LENGTH
150'
250'
350'
DISTANCE FROM
UNIT TO CONTROL
WIRING CODE
BLACK - BK
BROWN - BR
RED - R
ORANGE - O
YELLOW - Y
GREEN - G
BLUE - BL
PURPLE - PR
WHITE - W
75'
125'
175'
UDAP & UDAS SERIES
WD# 185139 REV #2 AG1
Form RZ-NA I-UDA, Mfg #195673 Rev 9, Page 23
MIN. RECOMMENDED
WIRE GAUGE
#18 GA. WIRE
#16 GA. WIRE
#14 GA. WIRE
Page 24
23. Wiring Diagrams (cont’d)
FIGURE 15B - Typical Wiring Diagram for Model UDAP or Model UDAS, Single Stage with
Optional Air Recirculation
LINE/1/60
W
(UDAS ONLY)
DISCONNECT SWITCH
BKBK
NEUTRAL
EAC/BLO
IND
NEUTRAL
SPARK
TRANSFORMER
W
BK
BK
W
G
GRD
SCREW
FAN MOTOR
BK
BR
CAPACITOR
(SEE NOTE #6)
W
(SEE NOTE #7)
SPARK GAP
BR/W
CAPACITOR
W1
G
W2
(OPT CL18) T874F THERMOSTAT
RH
Q674C SUBBASE (SEE NOTES #8 AND #9)
RC
G
W1
R
W2
TERMINAL STRIP
PR
Y
DOOR INTERLOCK
(UDAS ONLY)
RR
LIMIT CONTROL
RR
RR
FLAME ROLLOUT
(MODELS 30-125 ONLY)
ELECTRODE
GROUND
PRESSURE SWITCH
Y
GAS VALVE
BL
FLAME
FLAME
BR
FACTORY WIRING
FIELD WIRING
OPTIONAL FACTORY
WIRING
WIRE NUT
P3-1
P3-2
P3-3
P3-4
P3-5
P1-8
P1-3
P1-6
Y
P1-5
Y
P1-4
BL
P1-2
P1-7
R
P1-9
BR
SYSTEM TRANSFORMER
R
Y
G
W
R
C
3.0 AMP
FAST FLASH
1 FLASH
2 FLASH
3 FLASH
4 FLASH
STEADY OFF
SLOW FLASH WEAK FLAME
FAN O
E
TIM
90
120
160
180
Y
24V
BR
SW1
FUSE
ATO OR ATC
LED FLASH CODES
GREEN LED
NORMAL OPERATION NO CALL FOR HEATSTEADY ON
NORMAL OPERATION CALL FOR HEAT
IN LOCKOUT FROM FAILED IGNITIONS OR FLAME LOSSES
PRESSURE SWITCH DOES NOT CLOSE WITHIN 30 SECONDS
OF VENTER ENERGIZED
LIMIT SWITCH OR ROLLOUT SWITCH OPEN
PRESSURE SWITCH IS CLOSED BEFORE VENTER IS
ENERGIZED
INTERNAL CONTROL FAULT OR NO POWER
YELLOW LED
FLAME SENSEDSTEADY ON
UNDESIRED FLAME (VALVE OPEN & NO CALL FOR HEAT)FAST FLASH
FF DELAY
FF
O
O
FF
O
O
N
O
O
N
O
O
DSI CONTROL
FF
FF
N
N
VOLT
115/208/230
BK
L1NEUTRAL NEUTRAL L1COMSEC
LED
TEST
LED
OKFLAME
GY
G
W
VENTER
MOTOR
BR/W
G
G
BK
G
BR
1. SET THERMOSTAT AT LOWEST SETTING, FAN SWITCH AT "AUTO" POSITION.
2. TURN ON MANUAL GAS VALVE.
3. TURN ON POWER TO UNIT.
4. SET THERMOSTAT AT DESIRED SETTING.
5. LOW STAGE OF THERMOSTAT CALLS FOR HEAT, ENERGIZING THE FAN MOTOR.
6. HIGH STAGE OF THERMOSTAT CALLS FOR HEAT, ENERGIZING THE VENTER MOTOR.
7. VENTER PRESSURE SWITCH CLOSES, FIRING UNIT AT FULL RATE.
8. SET FAN SWITCH AT "ON" POSITION FOR CONTINUOUS FAN OPERATION.
9. IF THE FLAME IS EXTINGUISHED DURING MAIN BURNER OPERATION,
THE INTEGRATED CONTROL SYSTEM CLOSES THE MAIN VALVE AND
MUST BE RESET BY INTERRUPTING POWER TO THE CONTROL CIRCUIT
(SEE LIGHTING INSTRUCTIONS).
1. THE FOLLOWING CONTROLS ARE FIELD INSTALLED OPTIONS: THERMOSTAT
2. DOTTED WIRING INSTALLED BY OTHERS.
3. CAUTION: IF ANY OF THE ORIGINAL WIRING AS SUPPLIED WITH THE
APPLIANCE MUST BE REPLACED, IT MUST BE REPLACED WITH WIRING MATERIAL
HAVING A TEMPERATURE RATING OF AT LEAST 105° C. EXCEPT FOR SENSOR
LEAD WIRE, FLAME ROLLOUT AND LIMIT WIRING WHICH MUST BE 150° C.
4. USE 18 GA. WIRE FOR ALL WIRING ON THE UNIT.
5. LINE AND FAN MOTOR BRANCH WIRE SIZES SHOULD BE OF A SIZE TO PREVENT
VOLTAGE DROPS BEYOND 5% OF SUPPLY LINE VOLTAGE.
6. CAPACITOR IS REMOTE MOUNTED AND INCLUDED ONLY ON 115V MODELS
150-400 AND 208/230V MODELS 100-400.
7. CAPACITOR IS REMOTE MOUNTED AND INCLUDED ONLY ON MODELS 150 - 400.
8. SET THERMOSTAT SECOND STAGE ANTICIPATOR AT 0.6 AMPS. AND FIRST
STAGE ANTICIPATOR AT MINIMUM.
9. JUMPER THERMOSTAT TERMINALS G TO W1 AND RH TO RC IF FAN CONTROL FROM
THERMOSTAT FAN SWITCH IS DESIRED.
OPERATING SEQUENCE
NOTES
Form RZ-NA I-UDA, P/N 195673 Rev 9, Page 24
FIELD CONTROL WIRING
TOTAL WIRE
LENGTH
150'
250'
350'
DISTANCE FROM
UNIT TO CONTROL
WIRING CODE
BLACK - BK
BROWN - BR
RED - R
ORANGE - O
YELLOW - Y
GREEN - G
BLUE - BL
PURPLE - PR
WHITE - W
75'
125'
175'
UDAP & UDAS SERIES
WD# 185306 REV#3
MIN. RECOMMENDED
WIRE GAUGE
#18 GA. WIRE
#16 GA. WIRE
#14 GA. WIRE
Page 25
FIGURE 15C - Typical Wiring Diagram for Model UDAP or Model UDAS, Two Stage Gas Valve
W1
FACTORY WIRING
R
(OPT CL7) T874F THERMOSTAT
W2
Q674G SUBBASE (SEE NOTE #8)
G
W1
RH
(OPT CL18) T874F THERMOSTAT
RC
Q674C SUBBASE (SEE NOTE #8 AND #9)
W2
ALT.
HONEYWELL
TWO STAGE
GAS VALVE
BL
MV
STG
LOW
BR
C
STG
HIGH
O
HI
1. SET THERMOSTAT AT LOWEST SETTING, (FAN SWITCH AT "AUTO" POSITION, OPTION CL18 ONLY).
2. TURN ON MANUAL GAS VALVE.
3. TURN ON POWER TO UNIT.
4. SET THERMOSTAT AT DESIRED SETTING.
5. LOW STAGE OF THERMOSTAT CALLS FOR HEAT, ENERGIZING THE VENTER MOTOR.
6. VENTER PRESSURE SWITCH CLOSES, FIRING UNIT AT LOW RATE.
7. BURNER FLAME IS SENSED, AND IN 30 SECONDS THE FAN
8. HIGH STAGE OF THERMOSTAT CALLS FOR HEAT, FIRING UNIT AT FULL RATE.
9. SET FAN SWITCH AT "ON" POSITION FOR CONTINUOUS FAN OPERATION, OPTION CL18 ONLY.
10. IF THE FLAME IS EXTINGUISHED DURING MAIN BURNER OPERATION,
THE INTEGRATED CONTROL SYSTEM CLOSES THE MAIN VALVE AND
MUST BE RESET BY INTERRUPTING POWER TO THE CONTROL CIRCUIT
(SEE LIGHTING INSTRUCTIONS).
1. THE FOLLOWING CONTROLS ARE FIELD INSTALLED OPTIONS: THERMOSTAT
2. DOTTED WIRING INSTALLED BY OTHERS.
3. CAUTION: IF ANY OF THE ORIGINAL WIRING AS SUPPLIED WITH THE
APPLIANCE MUST BE REPLACED, IT MUST BE REPLACED WITH WIRING MATERIAL
HAVING A TEMPERATURE RATING OF AT LEAST 105° C. EXCEPT FOR SENSOR
LEAD WIRE, FLAME ROLLOUT AND LIMIT WIRING WHICH MUST BE 150° C.
4. USE 18 GA. WIRE FOR ALL WIRING ON THE UNIT.
5. LINE AND FAN MOTOR BRANCH WIRE SIZES SHOULD BE OF A SIZE TO PREVENT
VOLTAGE DROPS BEYOND 5% OF SUPPLY LINE VOLTAGE.
6. CAPACITOR IS REMOTE MOUNTED AND INCLUDED ONLY ON 115V MODELS
150-400 AND 208/230V MODELS 100-400.
7. CAPACITOR IS REMOTE MOUNTED AND INCLUDED ONLY ON MODELS 150 - 400.
8. SET THERMOSTAT FIRST STAGE ANTICIPATOR AT 0.6 AMPS AND
SECOND STAGE ANTICIPATOR AT 0.2 AMPS.
9. JUMPER THERMOSTAT TERMINALS RH TO RC.
TERMINAL STRIP
G
PR
W1
R
W2
HONEYWELL
O
OPERATING SEQUENCE
Y
RR
O
TWO STAGE
GAS VALVE
LO
STG
LOW
C
STG
HIGH
HI
NOTES
DOOR INTERLOCK
(UDAS ONLY)
LIMIT CONTROL
FLAME ROLLOUT
(MODELS 30-125 ONLY)
ELECTRODE
FIELD WIRING
OPTIONAL FACTORY
WIRING
WIRE NUT
RR
RR
PRESSURE SWITCH
Y
BL
BR
FLAME
FLAME
GROUND
MOTOR IS ENERGIZED.
P3-1
P3-2
P3-3
P3-4
P3-5
P1-8
P1-3
P1-6
Y
P1-5
Y
P1-4
P1-2
P1-7
R
P1-9
BR
SYSTEM TRANSFORMER
Y
G
W
R
C
TIM
120
160
180
Y
R
24V
BR
VOLT
115/208/230
BK
W
SW1
L1NEUTRAL NEUTRAL L1COMSEC
NEUTRAL
EAC/BLO
FUSE
3.0 AMP
ATO OR ATC
LED FLASH CODES
GREEN LED
NORMAL OPERATION NO CALL FOR HEATSTEADY ON
FAST FLASH
1 FLASH
2 FLASH
3 FLASH
4 FLASH
STEADY OFF
SLOW FLASH WEAK FLAME
FAST FLASH
FAN O
E
90
NORMAL OPERATION CALL FOR HEAT
IN LOCKOUT FROM FAILED IGNITIONS OR FLAME
PRESSURE SWITCH DOES NOT CLOSE WITHIN
30 SECONDS OF VENTER ENERGIZED
LIMIT SWITCH OR ROLLOUT SWITCH OPEN
PRESSURE SWITCH IS CLOSED BEFORE
VENTER IS ENERGIZED
INTERNAL CONTROL FAULT OR NO POWER
YELLOW LED
FLAME SENSEDSTEADY ON
UNDESIRED FLAME (VALVE OPEN & NO CALL
FOR HEAT)
ELAY
FF D
S W
1
FF
O
FF
O
N
O
N
O
DSI CONTROL
2
N
O
FF
O
FF
O
N
O
LED
TOTAL WIRE
LENGTH
150'
250'
350'
TEST
OKFLAME
LED
GY
WIRING CODE
BLACK - BK
BROWN - BR
RED - R
ORANGE - O
YELLOW - Y
GREEN - G
BLUE - BL
PURPLE - PR
WHITE - W
NEUTRAL
SPARK
TRANSFORMER
FIELD CONTROL WIRING
DISTANCE FROM
UNIT TO CONTROL
UDAP & UDAS SERIES
WD# 185244 REV #4 AG2
LINE/1/60
G
GRD
(UDAS ONLY)
BKBK
BK
W
W
BK
SCREW
FAN MOTOR
BK
(SEE NOTE #6)
SPARK GAP
DISCONNECT SWITCH
IND
75'
125'
175'
G
G
W
G
BR
BR/W
CAPACITOR
VENTER
MOTOR
W
BR
BR/W
CAPACITOR
(SEE NOTE #7)
MIN. RECOMMENDED
WIRE GUAGE
#18 GA. WIRE
#16 GA. WIRE
#14 GA. WIRE
BK
G
Form RZ-NA I-UDA, Mfg #195673 Rev 9, Page 25
Page 26
24. Check
Installation
and Startup
Check the
installation prior
to startup:
Check to be sure that all screws used to hold shipping brackets were re-
installed in the heater cabinet.
Check suspension. Unit must be secure and level.
Check clearances from combustibles. Requirements are in Paragraph 8.
Check vent system to be sure that it is installed according to the instructions
in the appropriate Vent Installation Manual as listed in Paragraph 1.
Check piping for leaks and proper gas line pressure. Bleed gas lines of
trapped air. See Paragraph 12.
Check electrical wiring. Be sure all wire gauges are as recommended. A
service disconnect switch should be used. Verify that fusing or circuit breakers are adequate for the load use.
Check polarity. Verify that line voltage exists between the black “L1” and
earth ground.
If installed in California, verify that California Warning Label is displayed
Heater
Startup:
WARNINGS: For your safety, read before operating. If you do
not follow these instructions exactly, a fire or explosion may
result causing property damage, personal injury, or loss of life.
• This appliance does not have a pilot. It is equipped with an ignition
device which automatically lights the burner. Do not try to light the
burner by hand.
• Before operating, smell all around the appliance area for gas. Be
sure to smell next to the floor because some gas is heavier than air
and will settle on the floor.
WHAT TO DO IF YOU SMELL GAS
• Do not try to light any appliance.
• Do not touch any electrical switch; do not use any phone in your
building.
• Immediately call your gas supplier fr om a neighbor's phone.
Follow the gas supplier's instructions.
• If you cannot reach your gas supplier, call your fire department.
• Use only your hand to turn the gas control ON/OFF knob on the
gas valve. Never use tools. If the valve ON/OFF knob will not turn
by hand, do not try to repair it. Call a qualified service technician.
Force or attempted repair may result in a fire or explosion.
Operating
Instructions and
Operating Sequence
Form RZ-NA I-UDA, P/N 195673 Rev 9, Page 26
1. Set thermostat at lowest setting.
2. Turn off all electric power to the appliance.
3. This appliance is equipped with an ignition device which automatically lights
• Should overheating occur, or the gas supply fail to shut off, turn off
the manual gas valve to the appliance before shutting off the
electrical supply.
• Do not use this appliance if any part has been under water. Immediately call a qualified service technician to inspect the appliance
and to replace any part of the control system and any gas control
which has been under water.
the burner. Do not try to light the burner by hand. Open the access door and
locate the gas control (ON/OFF) knob on the gas valve. (See FIGURE 16.)
Page 27
FIGURE 16 - Gas Valve
ON/OFF Control Knob
Top View
Gas Control
Knob
(shown in the
ON position)
Gas
Flow
Side View
Gas
Flow
4. Turn the gas control knob clockwise to "OFF".
5. Wait five (5) minutes to clear out any gas. Then smell for gas, including near
the floor. If you smell gas, ST OP! and follow the steps in the WARNINGS
printed above or on the Operating Label on the heater. If you do not smell
gas, proceed to the next step.
6. Turn the gas control knob counterclockwise to "ON".
7. Close the access door.
8. Turn on the electric power to the heater.
9. Set the thermostat to the desired setting.
NOTE: If the appliance does not operate, follow the instructions "To Turn Off
Gas to Appliance" printed below (and on the Operating Label on the heater) and
call your service technician.
10. Thermostat calls for heat, energizing the venter motor.
11. Venter pressure switch closes, firing the unit.
12. Burner flame is sensed and in 30 seconds after the gas valve is energized, the
fan motor is energized.
13. If the flame is extinguished during the main burner operation, the integrated
control system closes the main valve and must be reset by interrupting
power to the control circuit. (See lighting instructions on the heater.).
Check installation
after startup:
TO TURN OFF GAS TO THE APPLIANCE
1) Set thermostat to lowest setting
2) If service is to be performed, turn off all electric power to the appliance.
3) Open the access door.
4) Turn the gas control knob clockwise to "OFF". Do not force.
5) Close the access door.
Vent System Testing Procedure - Model UDAP
1. Seal any unused openings in the venting system.
2. Inspect the venting system for proper size and horizontal pitch, as required
in the National Fuel Gas Code, ANSI Z223.1 or CSA B149.1 and B149.2,
Installation Code for Gas Burning Appliances and Equipment, and the
venting installation manual. Determine that there is no blockage or restriction, leakage, corrosion or other deficiencies that could cause an unsafe
condition.
3. In so far as practical, close all building doors and windows and all doors
between the space where the heater is and other spaces of the building.
Turn on clothes dryers and exhaust fans, such as range hoods and bathroom exhausts, so they shall operate at maximum speed. Do not operate a
summer exhaust fan. Close fireplace dampers.
4. Light the heater following the lighting instructions. Adjust the thermostat
for continued operation. Verify that combustion products are venting
properly. After determining that the heater vents properly, return doors,
windows, exhaust fans, and fireplace dampers to their previous conditions.
If improper venting is observed, the venting system must be corrected.
With the unit in operation, measure valve outlet gas pressure. If operated at
high altitude, adjust outlet gas pressure for altitude.
See information and instructions in Paragraph 12.
Form RZ-NA I-UDA, Mfg #195673 Rev 9, Page 27
Page 28
Turn the unit off and on, pausing two minutes between each cycle. Observe
24. Startup
for smooth ignition.
(cont’d)
Place the "Owner's Envelope" containing the Limited Warranty, this booklet,
the venting manual, and any control or optional information in an accessible
location near the heater. Follow the instructions on the envelope.
DANGER: The gas burner in this gas-fired equipment is designed and equipped to pr ovide safe
controlled complete combustion. However, if the installation does not permit the burner to
receive the proper supply of combustion air , complete combustion may not occur. The result is
incomplete combustion which produces carbon monoxide, a poisonous gas that can cause death.
Safe operation of indirect-fired gas burning equipment requires a properly operating vent system
that vents all flue products to the outside atmosphere. FAILURE TO PROVIDE PROPER
VENTING WILL RESULT IN A HEALTH HAZARD WHICH COULD CAUSE SERIOUS
PERSONAL INJURY OR DEATH.
Always comply with the combustion air requirements in the installation codes and in Paragraph
9. Combustion air at the burner should be regulated only by manufactur er-provided equipment.
NEVER RESTRICT OR OTHERWISE ALTER THE SUPPLY OF COMBUSTION AIR TO
ANY HEATER. Model UDAP units installed in a confined space must be supplied with air for
combustion as required by Code and in Paragraph 9 of this heater installation manual.
MAINTAIN THE VENT OR VENT/COMBUSTION AIR SYSTEM IN STRUCTURALLY
SOUND AND PROPER OPERATING CONDITION.
MAINTENANCE
AND SERVICE
25. Maintenance
Schedule
NOTE: If replacement
parts are required,
use only factory-authorized
parts.
WARNING: If you turn off the power supply, turn off the gas. See Hazard
Levels, page 2.
The material contained in the MAINTENANCE AND SERVICE Section of this
manual is designed to aid a qualified service person in maintaining and servicing
this equipment. This heater will operate with a minimum of maintenance. To ensure long life and satisfactory performance, a heater that is operated under normal
conditions should be inspected and cleaned at the start of each heating season. If
the heater is operating in an area where an unusual amount of dust or soot or other
impurities are present in the air, more frequent maintenance is recommended.
When any service is completed, be careful to reassemble correctly to ensure that
no unsafe conditions are created. When re-lighting, always follow the lighting
instructions on the heater.
Maintenance Schedule - The following procedures should be carried out at least
annually (See FIGURE 18 and Paragraphs 26-39.):
• Clean all dirt, lint, and grease from the combustion air opening (UDAP) and
venter assembly .
• Clean all dirt, lint, and grease from the fan blade, fan guard, and motor.
• Check the heat exchanger both internally and externally.
• Check the burner for scale, dust, or lint accumulation. Clean if needed.
• Check the vent or vent/combustion air system for soundness. Clean openings.
Replace any parts that do not appear sound.
• Check the wiring for any damaged wire. Replace damaged wiring. (See Paragraph 14 for replacement wiring requirements.)
Form RZ-NA I-UDA, P/N 195673 Rev 9, Page 28
Page 29
26. Heat
Exchanger
Maintenance
27. Burner
Maintenance
Burner Removal
Instructions (Refer
to FIGURE 17.)
FIGURE 17 - Burner
Removal (UDAP
illustrated; same process
for both UDAP and UDAS)
2
This heater is equipped with a TCORE
6,889,686).
Remove any external dirt or dust accumulation. V isually check the heat exchanger
for cracks and holes. If a crack or hole is observed, replace the heat exchanger.
NOTE: Inspection of the lower portion of the heat exchanger is done with the
burner removed. See the Burner Service section below for information on inspecting the lower portion of the heat exchanger.
This heater is equipped with a TCORE
Inspect the burner/control compartment annually to determine if cleaning is necessary. If there is an accumulation of dirt, dust, and/or lint, clean the compartment
and follow the instructions below to remove and clean the burner.
®
heat exchanger (U.S. Patent No.
2
®
burner (U.S. Patent No. 6,889,686).
CAUTION: Use of eye protection is recommended.
1. Outside the cabinet, shut the gas supply off at the manual valve ahead of the
union.
2. Turn off electric supply.
3. Disconnect the gas supply at the union outside of the cabinet.
4. Remove the access panel.
5. Disconnect the Gas Train and Move Out of the Way - At the gas valve,
mark and disconnect the wires. Carefully remove the burner orifice and
orifice adapter locking nut. Slide the orifice adapter out through the bracket
on the burner pushing the gas train to the right. This will move the gas train
out of the way.
6. Move the Control Assembly - Remove the two screws holding the control
assembly bracket. Being careful not to disconnect any wires, slide the control
assembly to the right.
7. Remove Secondary Air Baffles (Sizes 60-400 only) - Vertical along the right
side of the burner, locate the flat plate(s) identified as the secondary air
baffle(s). The quantity of baffles could be one to four depending on heater
Burner Assembly
Secondary Air Baffle
(Qty varies per size.)
Mark locations before removing.
Burner Body Support (at least two per unit) - Remove screw attaching
to secondary air shield. Support remains attached to burner.
Secondary Air Shield
Burner
Orifice
Venturi Tube
Slide right; rotate
inward; pull out
Slide Right
Control Bracket Screws Loosen bracket; slide right.
Gas Valve
Disconnect gas train at
orifice and outside the
heater; slide to the right.
Orifice Adapter Locking Nut
Form RZ-NA I-UDA, Mfg #195673 Rev 9, Page 29
Page 30
27. Burner
Maintenance
(cont’d)
Burner Removal
(cont’d)
size. Each baffle is held in place by one screw. For re-assembly, on the
secondary air shield, mark the location (top and bottom) of each baffle.
Remove all baffles.
8. Remove Burner Assembly
a) Locate the burner body supports. Depending on the size, the burner will
have two or more supports. At each support, remove the one screw that
attaches it to the secondary air shield
b) Holding the venturi tube, slide the entire burner assembly slightly to the
right to disengage the burner from the supports on the left. Then rotate
the open end of the venturi tube inward toward the heater. Carefully pull
the burner assembly out of the cabinet.
Inspect and Clean the
Burner
Re-Install the Burner
With the burner assembly removed, shine a flashlight on the burner ribbons. Look
for carbon buildup, scale, dust, lint, and/or anything that might restrict flow through
the spaces between the burner ribbons. Holding the burner assembly so that any
foreign material will fall away from the burner, use a stiff bristle brush to loosen
and remove any foreign material(s). If the burner is excessively dirty, remove one
of the burner end caps. Remove the four screws that hold the end cap to the burner
housing. Lightly tap the end cap to remove it.
Clean all foreign material from the burner and venturi. After the burner is thoroughly clean, replace the end cap making certain that it is tight against the burner
housing. NOTE: If any of the burner components are damaged or deteriorated,
replace the burner assembly.
Inspect the Lower Portion of the Heat Exchanger (with burner
assembly removed)
At the burner flame entrance of each tube, shine a bright light into each heat
exchanger section. With the light shining into the heat exchanger, observe the
outside for visible light. Repeat this procedure with each heat exchanger section.
If any light is observed, replace the heat exchanger.
Instructions to Re-Install the Burner (Refer to FIGURE 17)
1. Attach the Burner Assembly - Holding the venturi tube, slide the entire
burner assembly into position. Align the supports on the left side with the
slots in the burner shield; sliding the supports into the slots. On the right, reattach each burner body support to the secondary air shield.
2. Attach the Secondary Air Baffles (Sizes 60-400 only) - Re-attach the
secondary air baffles as marked. Baffles may be different sizes and each
must be attached in the correct location.
3. Attach the Control Assembly - Carefully slide the control assembly into
position. Re-attach with the same screws. Check to be sure all wire connections are secure.
4. Attach the Gas Train - Slide the gas train so that the orifice adapter is
through the bracket. Fasten the gas train to the bracket with the locking nut.
Install the gas orifice. Re-connect the wires to the gas valve.
5. Close the access panel.
6. Reconnect the gas supply at the union outside of the cabinet. Leak test the
connection with leak detecting solution.
7. Turn on the electric and the gas. Check for proper operation.
28. Burner
Orifice
Form RZ-NA I-UDA, P/N 195673 Rev 9, Page 30
Burner orifice usually only needs to be replaced when installing a gas conversion
kit. If ordering a replacement orifice only, give BTUH content and specific gravity of gas, as well as the model and serial number of the unit. When removing or
replacing the burner orifice be careful not to damage the venturi tube and/or the
bracket.
Page 31
FIGURE 18 - Location of Controls
Flame Rollout Switch
(Sizes 30-125)
Burner Assembly
Ignitor
Transformer
Circuit Board
(DSI Integrated
Control Module)
Flame Sensor
High Temperature
Limit Control
Control Panel Assy
located on the
Control Compartment
Bottom
Sizes 30-125
Sizes 150-400
Optional
Fan Motor
Capacitor
Pressure Switch
Gas Valve
Transformer
Circuit Board
(DSI Integrated
Control Module)
Venter Motor (Size 30-75
illustrated. Venter motor
is in the same location for
all models, but appearance is different.)
Model UDAS has a
collar for combustion
air pipe (not illustrated)
Interlock Door
Switch - UDAS only
Fan
Motor
Terminal
Board (24V)
Disconnect Switch
- UDAS only
Electrical Box - UDAS only
Remove cover to connect
supply and access
disconnect switch wires .
Always replace cover.
Venter Motor
Capacitor
Fan Motor
Capacitor
29. Ignition
System
FIGURE 19 - DSI
Integrated Control Module
(Circuit Board)
DSI Integrated Control Module (circuit board) - See FIGURE 19. The module
monitors the operation of the heater including ignition. The only replaceable component is the 3 amp Type ATC or ATO fuse. If the fuse is blown, the problem is
most likely an external overload. Correct the problem and replace the fuse.
Do not attempt to disassemble the control module. However, each heating season
check the lead wires for insulation deterioration and good connections.
Proper operation of the direct spark ignition system requires a minimum flame
signal of 1.0 microamps as measured by a microampmeter.
For further information and check out procedure on the direct spark ignition system, refer to Paragraph 20 and the Troubleshooting Flow Chart in Paragraph 40.
Only replaceable part
is a Type ATC or ATO 3
amp fuse (Color Code
Violet), P/N 201685
Form RZ-NA I-UDA, Mfg #195673 Rev 9, Page 31
Page 32
29. Ignition
System
Ignitor - Refer to FIGURE 18 and locate the ignitor. Disconnect the wire; remove the screw and the ignitor. Clean the ignitor assembly with an emery cloth.
Spark gap must be maintained to 1/8". See FIGURE 20.
(cont’d)
Ignitor
Flame Sensor
30. Fan Motor ,
Fan Blades,
and Guard
FIGURE 21 - Fan Blade
Position on the Shaft
Dimension A
inches mm
Size
30
45
60
75
100
125
150
175
200
225,
250,
300
350
400
125
9/1614
1-1/238
2-1/854
2-3/860
2-5/16 59
2-3/860
2-1/854
1-5/867
251
1-7/848
1-3/835
Fan
Blade
FIGURE 20 - Ignitor
showing required
Spark Gap
1/8 inch
(3.2mm)
measurement
IMPORTANT: When re-assembling, the brown ground wire must remain attached
to the ignitor .
CAUTION: Due to high voltage on the spark wire and electrode,
do not touch when energized. See Hazard Levels, page 2.
Flame Sensor - Refer to FIGURE 18 and locate the flame sensor. Disconnect the
wire; remove the screw and the flame sensor. Clean with an emery cloth.
Remove dirt and grease from the motor, the fan guard, and blades. Use care when
cleaning the fan blades to prevent causing misalignment or imbalance. Check that
the hub of the fan blades is secure to the shaft.
Follow these instructions for replacement of the fan guard, fan motor and/or fan
blades.
1. If the heater is installed, turn off the gas and disconnect the electric power.
2. Open the access door and disconnect the fan motor wires, capacitor wires at the
capacitor, and ground screw.
3. Remove the assembled parts (the fan guard, the motor and the fan blade).
A
Fan
Motor
tioned properly.
5. Reconnect the fan motor wires according to the wiring diagram and close the
access panel.
6. Restore power to the heater and turn on the gas. Light, following the instructions
on the lighting instruction plate. Check for proper operation.
4. Disassemble and replace whatever parts are needed and reassemble using whatever part(s) are being replaced and the original
parts.
Be sure the fan blade is in the proper position on the shaft; refer to
the illustration and table in FIGURE 21.
Position the assembly on the heater. Attach the fan guard.
Rotate the fan blade to check for adequate clearance. If adjustment
is required, loosen the mounting screws, re-position the fan guard,
and tighten the screws. Rotate the fan blade and re-check for adequate clearance. Repeat this procedure until the assembly is posi-
31. V enter Motor
and Wheel
Replacement Instructions
Form RZ-NA I-UDA, P/N 195673 Rev 9, Page 32
Remove dirt and grease from the motor casing, the venter housing, and the venter
wheel. Venter motor bearings are permanently lubricated. Follow these instructions for replacement of the venter motor and wheel assembly. Keep all hardware
removed to be used in re-assembling and installing the replacement parts.
1. Turn off the gas and disconnect the electric power.
2. Open the burner/control compartment access panel.
3. Disconnect the three venter motor wires at the DSI control, capacitor wires at
4. Sizes 30 and 45 - Disconnect the gas train and move it out of the way. Discon-
the capacitor (if applicable), and ground screw (located on the control panel).
nect the gas supply at the union outside of the cabinet. At the gas valve, mark
and disconnect the wires. Carefully remove the burner orifice and orifice adapter
locking nut. Slide the orifice adapter out through the bracket on the burner pushing the gas train to the right. This will move the gas train out of the way.
Page 33
FIGURE 22 - Venter Wheel
Position on Shaft
5. Holding the venter motor, remove the three or four screws that attach the venter
motor mounting plate to the venter housing. Remove the motor and wheel assembly from the heater.
6. Re-assemble with the replacement venter motor and wheel assembly. See FIG-URE 22.
7. Follow the wiring diagram to connect the venter wires.
8. Sizes 30 and 45 - Reconnect the gas supply at the union outside of the cabinet.
Leak test the connection with leak detecting solution.
9. Replace the access panel. Restore power to the heater and turn on the gas. Light,
following the instructions on the lighting instruction plate. Check for proper
operation.
Venter Wheel,
Sizes 30-75
32. Operating
Gas V alve
Venter Motor Plate
Fan
Motor Mounting
Bracket
Motor
Sizes
30-75
5/16 (8mm) inside
The gas valve requires no field maintenance except careful removal of external
dirt accumulation and checking of wiring connections. Instructions for testing
pressure settings are in Paragraph 12.
WARNING: The operating valve is the
prime safety shutoff. All gas supply
lines must be free of dirt or scale before
connecting to the unit to ensure positive
closure. See Hazard Levels, page 2.
33. Combustion
Air Pressure
Switch
Venter Wheel,
Sizes 100-175*
Single
Stage
Gas
Valve
Venter Motor Plate
Fan
Motor Mounting Bracket
Motor Sizes
100-400
*Venter wheel has
different appearance
on Sizes 200-400.
Motor spacing is
the same.
5/16 (8mm) inside
Optional
Two
Stage
Gas
Valve
See FIGURE 18, page 31, for location. (NOTE: Depending on date of
manufacture and size, pressure switch may not be in the location indicated. Check the control bracket on the bottom of the compartment or
further down on the compartment wall.) If it is determined that the pressure switch needs replacing, use only the factory-authorized replacement
part that is designed for the model and size of heater being serviced.
NOTE: A unit operating above 6000 ft elevation requires a high altitude
pressure switch. See Paragraph 7.
34. Limit Control
35. Door Switch
- UDAS only
36. T ransformer
If it is determined that the limit control needs replacing, use only a factory-authorized replacement part that is designed for the size of heater.
For approximate limit location, see FIGURE 18, page 31.
If it is determined that the door switch needs replacing, use only a factory-authorized replacement part that is designed for the heater.
For approximate switch location, see FIGURE 18, page 31.
See FIGURE 18, page 31, for location. Use a voltmeter to verify that
there are 24 volts output from the transformer. If the transformer is not
functioning, it must be replaced. Use a replacement transformer identical to the factory-installed model.
Form RZ-NA I-UDA, Mfg #195673 Rev 9, Page 33
Page 34
37. Flame
Rollout
Switch Sizes 30-125
only
For location, see
FIGURE 18, page 31.
The cause of a flame rollout switch activating must be determined. Activation of
the manually reset flame rollout switch could be caused by one or more of the
following:
• Restricted or plugged
heat exchanger
• Too much building
exhaust
• Manifold gas pressure
too high
• Restricted combustion air inlet or exhaust
outlet in combination with a defective
pressure switch
• Electrical power interruption during operation
• Unit being operated with a line voltage
disconnect (a 24-volt thermostat is required)
If a flame rollout switch trips, inspect the burner/control compartment for signs of
excessive heat and burned wiring.
If the compartment appears normal, reset by depressing the red button on
the switch. 15 to 20 minutes are required for the switch to cool sufficiently for
resetting. A distinct click will be felt when the switch resets. Operate the furnace. If the flame rollout switch trips again, determine and correct the cause
before resetting the switch.
If there is damage to the control compartment, repairs must be made before
resetting the switch.
If it is determined that the flame rollout switch needs replacing, use only the factory-authorized replacement part that is designed for that size of heater.
38. Disconnect
Switch UDAS only
39. V ent or V ent/
Combustion
Check the complete system at least once a year. Inspection should include all joints,
seams, concentric adapter box (UDAS), inlet air guard or inlet air cap (UDAS), and
the vent terminal cap. Clean openings. Replace any defective parts.
Air System
40. T roubleshooting
DSI Integrated Control Module
(Circuit Board) T rial
Troubleshooting
YESNO
Flowchart
Is there
minimum flame current
at the control
module?
NO
Check connections to flame
sensor and/or moisture in the
burner assembly.
YES
Is there minimum
flame current at the
flame sensor?
Replace control
module.
YESNO
Does gas
Is the flame
sensor corroded?
Is the sensor
located in flame
correctly?
Reposition
flame sensor.
The disconnect switch is located in the sealed electrical box inside the control compartment with the toggle on the rear of the heater.
If it is determined that the disconnect switch needs replacing, use only the
factory-authorized replacement part that is designed for the heater. Always
replace electrical box cover.
Trial for Ignition
Call for Heat
Is there a
spark across gap at
ignitor?
YESNO
Is gas
flowing?
Is there
spark voltage at
control?
NO
Is there 24V P1-2
to power control?
NO
Check wiring
and/or 24VAC
transformer output.
YES
YES
Check high
voltage wire
continuity.
Replace
control
module.
ignite?
YESNO
YES
Clean flame
sensor.
NO
YES
Replace flame
sesnsor.
NO
Form RZ-NA I-UDA, P/N 195673 Rev 9, Page 34
Check gas pressure
and supply voltage.
If either are low,
correct and repeat
startup.
YES
Is the ignitor
position correct in the
gas flow?
NO
Reposition
spark ignitor.
Replace gas
valve.
Check wiring and
connections to
gas valve.
YES
YESNO
Is there
24VAC at the gas
valve?
NO
Is there 24VAC
from gas valve output on
control module to
chassis?
Replace
ignition
control
module.
Page 35
Check the Lights on
b)
b)
the DSI Integrated
Control Module
(Circuit Board)
The integrated circuit board monitors the operation of the heater and includes two
LED signal lights that indicate normal operation and various abnormal conditions.
If the heater fails to operate properly , check this signal to determine the cause and/
or to eliminate certain causes. LED is visible through viewport on Model UDAS.
Remove access panel on Model UDAP. See operating sequence in Paragraph 20.
Do not attempt to repair the DSI integrated control module (circuit board); the only
IMPORTANT: When using a
field replaceable component is the fuse.
multimeter to troubleshoot the
24 volt circuit, place the
meter’s test leads into the 5 or 9
pin connectors located on the
ignition control. Do not remove
connectors or terminals from
the electrical components.
Doing so can result in misinterpreted readings due to the
ignition control board’s fault
mode monitoring circuits.
Control Status - Green LED Codes
Steady ON..Normal Operation, No call
for heat
Fast Flash...Normal Operation, Call for
heat
1 Flash........System Lockout, Failed to
detect or sustain flame
2 Flashes ....Pressure Switch Did Not
Close within 30 Seconds of
Venter Motor
3 Flashes ....High Limit or Flame
Rollout Switch Open
General T roubleshooting
PRO BLEMPROBABLE CAUSEREMEDY
Venter moto r
will not start
1 . No power to unit.1 . Turn on powe r; chec k supply fuses or main ci rcuit breaker. Turn on built-
in disconnect switch (Model UDAS only); replace switch if not operating.
4 Flashes ....Pressure Switch is Closed
Before Venter Motor is
Energized
Steady OFF Blown fuse, No Power, or
Defective Board
Flame Status - Yellow LED Codes
Steady ON..Flame is sensed
Slow Flash .Weak flame (current below
1.0 microamps ± 50%)
Fast Flash...Undesired Flame (valve
open and no call for heat)
Burner will
not light
2. No 24 volt power to integrated circuit board. 2. Turn up thermostat; check control transformer output.
3 . Inte grated circuit boar d fuse blown.3. Corre ct c a use. Re place f use (type ATC or AT O, 32VDC, 3A).
4 . No power to ve nt e r motor.4 . Ti g hte n c onne c t ions at circ uit board and/ or m o tor ter mina ls.
6. Defecti ve venter motor.6. Replace venter motor. S ee Paragraph 31.
1 . Manual valve not open.1. Open manual valve.
2. Air in the gas line.2. Bleed gas line (initial startup only).
3 . Gas pressure too high or too low.3. Supply pre ssur e should be 5" - 14" w.c. for natur al ga s or 11" - 14 " w.c .
for propane gas.
4. No Spark:4.
a) L oose wir e connections.a) Be certain all wire c onn ections are solid.
b) Transf ormer fai lure.b) B e sure 24 vol ts is avai lable.
c) Incorrect spark gap.c) Maintain spark gap at 1/8".
d) Spar k cable shorte d to ground.d) Replace worn or ground e d spark ca ble.
e) Spark electrode shorted to ground.e) Repl ace if cer amic spark electrode is cracked or grounded.
f) Burner not groun ded.f) Make certain integrate d circuit board is gr ou nded to ign itor.
g) Cir c u it boar d not grounded.g) M a ke certai n integrat e d c ircuit board is ground e d to furnace chassi s.
h.) Unit not properly grounde d .h.) Make certain unit is properly field grounded to earth ground and
prop e rly pha sed (L 1 to hot lea d L2 to neut ral ).
i) Integrated cir cuit board fuse blown.i ) Correct cause. R eplace fuse (type ATC or ATO , 32VDC, 3A).
j .) Faul ty intergr a t e d c ircuit board.j) If 24 volt is avail a ble to the i nte grated c irc uit board and all other causes
have been eli minated, replace board.
5 . L oc kout device inter rupti ng c ont rol c ircuit by
above causes.
6. Interl ock door switch open (UDAS only).6 . Close access door or r eplace switch.
7. Combustion air pr oving switc h 7.
not closing.a) Make sure unit is properly vented.
8. Faulty combustion air proving switch.8. Replace combustion air provi ng switch.
9. Mai n val ve not operating.9.
a) Defective valve.a) If 24 volt is measured at the valve connections and valve remains closed,
Loose wire c onnecti ons
5 . Reset lockout by interrupting control at the t hermostat or main power.
b) Rem ove obstructions from vent.
c) Replace faulty tubing to pressure switch.
repl ace valve.
C heck and tighten all w iring connections.
Form RZ-NA I-UDA, Mfg #195673 Rev 9, Page 35
Page 36
40. T roubleshooting (cont’d)
p
PROBLEM (cont'd)PROBABLE CAU SE (cont'd)REMEDY (cont'd)
Burner will not light
(cont'd )
Burner cycle on and of f
No heat (Heater
Operati ng)
Fan or venter motor will
not run
F an o r venter motor turns
on and off while burner is
operating
F an o r venter motor cuts
out on overload
9. Integra t ed circuit board does not power main
valve.
a) Loose wi re connections.a) Check and tighten all wi ring connecti ons.
b) Flame sensor grounded.b) B e certain flame sensor lead is not grounded or insulation or ceramic
c) Incorrect gas pressure.c) Supply pressure should be 5" - 14" w.c. for natural gas or 11" - 14"
d) C r acked ceramic at sensor.d) Replace sensor.
1 . Gas pre ssure too hi gh o r too l ow.1. Supply pr e ssur e should be 5" - 14" w. c. f or natural ga s or 11" - 14"
2. Bur ner not grounded2. Make certa in integrated ci rcuit board is grounded to i gnitor.
3. Circuit board not grounded.3 . Make cer tain integrated ci rcuit board is grounded to furnace chassis.
4. Faulty integrated circuit board4. If 24 volt is available to the integrated circuit board and al l other
5. Combustion air proving switc h 5.
not closing.a) Ma ke sure uni t is properly vented.
6. F a ul ty combustion air proving switch.6. Replace combustion air pr ovi ng swi tch.
7. Flam e sensor gr ounded.7 . B e c e rtai n flame sensor lead is not grounded or insulation or ceramic
8. Cracked ceramic at sensor.8. R eplace sensor.
9. Incorr ec t polarity.9. Reverse line volt leads to integrated cir cuit board.
10. Pi n ter minal l oose on 9 pin plug.10. R eplace wire harness.
1. Incorrect valve outlet pressure or orifi ce.1. Check valve outl e t pressure. See R ating plate for manifol d pressure.
2. Cycling on limit control.2. Chec k air throughput.
3. Improper thermostat location or adjustment. 3. See thermostat manufactur er's instructions.
1. Circuit o
2. D e fective integrated ci r cuit board.2. Replace board.
3. D e fective m otor or starter. 3. Replace motor or starter.
1. Motor overload device cycl ing on and off. 1. Check m otor load against m otor r a ting plate. Replace motor if needed.
1. Low or high voltage suppl y.1. Correct e lectric supply.
2. D e fective m otor.2. Replace motor.
3. Poor airflow. 3. C l ean motor, fan, fan guard, filter, and coils.
4. D e fective bearing or lubrication. 4. Lubricate bear ings (motor perm itting) or replace motor.
en.1. Check wiring and connections.
9.
is not cracked. Replace as requir ed.
w. c. for propane gas.
w. c. for propane gas.
causes have been elim inated, replace board.
b) Remove obstr uct ions from vent.
c) Replace faul ty tubing to pressure switch.
is not cracked. Replace as requir ed.
FOR SERVICE OR REPAIR, FOLLOW THESE STEPS IN ORDER:
FIRST:Contact the Installer
Name __________________________________________________________
Address_________________________________________________________