This manual must only be
used by a qualified heating
installer / service technician.
Read all instructions,
including this manual and
the Crest Installation and
Operation Manual, before
installing. Perform steps in
the order given. Failure to
comply could result in severe
personal injury, death, or
substantial property damage.
Gas Valve Adjustment Procedure .................................... 53
Revision Notes .................................................. Back Cover
Hazard definitions
The following defined terms are used throughout this manual to bring attention to the presence of hazards of various risk levels or
to important information concerning the life of the product.
DANGER
WARNING
CAUTION
CAUTION
NOTICE
DANGER indicates an imminently hazardous situation which, if not avoided, will result in death or serious
injury.
WARNING indicates a potentially hazardous situation which, if not avoided, could result in death or serious
injury.
CAUTION indicates a potentially hazardous situation which, if not avoided, may result in minor or moderate
injury.
CAUTION used without the safety alert symbol indicates a potentially hazardous situation which, if not
avoided, may result in property damage.
NOTICE indicates special instructions on installation, operation, or maintenance that are important but not
related to personal injury or property damage.
2
Please read before proceeding
Service Manual
WARNING
Installer – Read all instructions, including
this manual and the Crest Installation
and Operation Manual, before installing.
Perform steps in the order given.
User – This manual is for use only by
a qualified heating installer/service
technician. Refer to the Crest User’s
Information Manual for your reference.
Have this boiler serviced/inspected by
a qualified service technician at least
annually.
Failure to comply with the above could
result in severe personal injury, death or
substantial property damage.
NOTICE
Handling ceramic fiber materials
REMOVAL OF COMBUSTION CHAMBER LINING
WARNING
The combustion chamber insulation in this appliance contains ceramic fiber material. Ceramic fibers can
be converted to cristobalite in very high temperature applications. The International Agency for Research
on Cancer (IARC) has concluded, “Crystalline silica in the form of quartz or cristobalite from occupational
sources is carcinogenic to humans (Group 1).” Normal operating temperatures in this appliance are below
the level to convert ceramic fibers to cristobalite. Abnormal operating conditions would have to be created
to convert the ceramic fibers in this appliance to cristobalite.
When calling or writing about the boiler
– Please have the boiler model and serial
number from the boiler rating plate.
Consider piping and installation when
determining boiler location (see the Crest
Installation and Operation Manual).
Any claims for damage or shortage
in shipment must be filed immediately
against the transportation company by the
consignee.
The ceramic fiber material used in this appliance is an irritant; when handling or replacing the ceramic
materials it is advisable that the installer follow these safety guidelines.
Avoid breathing dust and contact with skin and eyes.
• Use NIOSH certified dust respirator (N95). This type of respirator is based on the OSHA
requirements for cristobalite at the time this document was written. Other types of respirators may
be needed depending on the job site conditions. Current NIOSH recommendations can be found on
the NIOSH website at http://www.cdc.gov/niosh/homepage.html. NIOSH approved respirators,
manufacturers, and phone numbers are also listed on this website.
• Wear long-sleeved, loose fitting clothing, gloves, and eye protection.
Apply enough water to the combustion chamber lining to prevent airborne dust.
Remove the combustion chamber lining from the appliance and place it in a plastic bag for disposal.
Wash potentially contaminated clothes separately from other clothing. Rinse clothes washer
thoroughly.
NIOSH stated First Aid.
Eye: Irrigate immediately.
Breathing: Fresh air.
3
Please read before proceeding
When servicing boiler –
• To avoid electric shock, disconnect electrical supply
before performing maintenance.
• To avoid severe burns, allow boiler to cool before
performing maintenance.
Boiler operation –
• Do not block flow of combustion or ventilation air to
the boiler.
• Should overheating occur or gas supply fail to shut off,
do not turn off or disconnect electrical supply to
circulator. Instead, shut off the gas supply at a location
external to the appliance.
• Do not use this boiler if any part has been under water.
The possible damage to a flooded appliance can be
extensive and present numerous safety hazards. Any
appliance that has been under water must be replaced.
Service Manual
Boiler water –
• Thoroughly flush the system (without boiler
connected) to remove sediment. The high-efficiency
heat exchanger can be damaged by build-up or
corrosion due to sediment.
• Do not use petroleum-based cleaning or sealing
compounds in the boiler system. Gaskets and seals in
the system may be damaged. This can result in
substantial property damage.
• Do not use “homemade cures” or “boiler patent
medicines”. Serious damage to the boiler, personnel,
and/or property may result.
• Continual fresh make-up water will reduce boiler life.
Mineral buildup in the heat exchanger reduces heat
transfer, overheats the stainless steel heat exchanger, and
causes failure. Addition of oxygen carried in by makeup
water can cause internal corrosion. Leaks in boiler
piping must be repaired at once to prevent the
introduction of makeup water.
Freeze protection fluids –
• NEVER use automotive antifreeze. Use only inhibited
propylene glycol solutions which are specifically
formulated for hydronic systems. Ethylene glycol is
toxic and can attack gaskets and seals used in hydronic
systems.
4
What is in this manual?
Service Manual
Service
Near boiler piping
• Typical system components
The Crest boiler display
• Display panel readout, buttons and their functions
Control module inputs
• Control module inputs and options
Control module outputs
• Control module outputs and options
General
• How the boiler operates
• How the control module operates
• Access modes -- user and installer
• Sequence of operation -- HWG/space heating
Control panel menu access
• Accessing programming mode and locating menus
(See separate guide covering the PC interface.)
Maintenance
• Service and maintenance schedules
• Address reported problems
• Inspect boiler area and boiler interior
• Clean condensate trap
• Check all piping for leaks
• Check air openings
• Flue vent system and air piping
• Check water system
• Check expansion tank
• Check boiler relief valve
• Inspect ignition electrode
• Check ignition ground wiring
• Check all boiler wiring
• Check control settings
• Perform start-up and checks
• Check burner flame
• Check flame signal
• Check flue gas temperature
• General maintenance
• Review with owner
• Cleaning boiler heat exchanger
• Oiled bearing circulators
Control panel parameter access
• Accessing and changing parameters from the display panel
Quick start information -- parameter
table
• An index of available adjustments and readouts, where to
access them and where to find detailed information.
Crest boiler operation
• Initial Setup
• Set Points
• Outdoor Reset
• Ramp Delay
• BMS
• Advanced Setup
• SH Night Setback
• HWG Night Setback
• Cascade
• Pumps
• Service Notification
Troubleshooting
• Troubleshooting table - No display
• Checking temperature sensors
• Sensor tables
• Troubleshooting table - Fault messages displayed on
boiler interface
• Combustion analysis procedure
• Gas valve adjustment procedure
5
Service Manual
1 Service
Boiler piping
This piping reference is included to specify the Boiler Piping specific to the Crest boiler. This piping scheme is important for
proper operation of the SMART TOUCH control. See the Crest Installation and Operation Manual for more detailed piping
diagrams.
Single Boiler - Recommended - Primary / Secondary Piping with a Hot Water Generator
FROM SYSTEM
SYSTEM RETURN
SENSOR
12"
MAX
HOT WATER
GENERATOR
RELIEF
VALVE
BALL VALVE
(TYPICAL)
AIR SEPERATOR
DRAIN PORT
(TYPICAL)
SYSTEM SUPPLY
SENSOR
SYSTEM
CIRCULATOR
BOILER
DRAIN
WATER
GENERATOR
CIRCULATOR
Y-STRAINER
(RECOMMENDED)
BOILER PUMP
FLOW CHECK
VALVE (TYPICAL)
Single Boiler - Alternate - Full Flow System Piping
RELIEF
VALVE
BALL VALVE
(TYPICAL)
FROM SYSTEM
BOILER DRAIN
Y-STRAIN ER
(RECOMMENDED)
EXPANSION
TANK
PRESSURE
REDUCING VALVE
PRESSURE
GAUGE
AIR SEPERATOR
DRAIN PORT
(TYPICAL)
SYSTEM
CIRCULATOR
BACK FLOW
PREVENTER
TO SYSTEM
MAKE UP
WATER
EXPANSION
TANK
PRESSURE
GAUGE
PRESSURE
REDUCING VALVE
BACK FLOW
PREVENTER
TO SYSTEM
MAKE UP
WATER
6
Service Manual
1 Service (continued)
The Home Screen displays status, modulation rate, outlet water temperature, inlet water temperature, flue temperature, system
supply temperature, system return temperature, outdoor air temperature, and domestic hot water tank temperature.
The boiler can be started and stopped by pressing the ON/OFF button. The Boiler Status Screen and Main Menu Screen can be
accessed by pressing the appropriate button.
Home Screen
When the ON/OFF switch is turned to the ON position,
the first screen visible on the LCD display will be the Home
Screen. This screen displays the current status of the Crest
boiler. The following items can be viewed or interacted with
on the Home Screen:
On/Off button - Pressing this button allows the boiler to be
placed in either Manual Shutdown Mode or Standby Mode.
Status - This line shows the current operating status of the
Crest boiler and the current set point.
Outlet Water Temperature - This is the boiler outlet
temperature.
Inlet Water Temperature - This is the boiler inlet temperature.
System Supply Temperature - This is the water temperature
as measured by the system supply sensor located in the
downstream piping (if connected).
System Return Temperature - This is the water temperature
measured by the system return sensor located in the upstream
piping (if connected).
Outside Air Temperature - This is the outdoor air temperature
(if connected).
HWG Temperature - This is the temperature as measured by
the tank sensor in the hot water storage tank (if connected).
Flue Temperature - Temperature measured by the flue sensor.
Time - The time is displayed in the lower left-hand corner of the
display. Reference this manual for Night Setback parameters
and more information regarding adjusting the date and time.
Boiler Status button - Pressing this button brings up the Boiler
Status Screen. This screen shows the status of the various
safeties, inputs, and outputs to the control module. Reference
this manual for more information regarding this screen.
Main Menu button - Pressing this button brings up the Main
Menu Screen. From this screen navigation to nine (9) other
screens is possible.
Modulation button - Pressing this button brings up the
Modulation Screen. This screen shows overall boiler
modulation, individual fan speeds, and flame currents.
Modulation Percentage - Displays the current boiler firing
rate.
7
1 Service
1 Service
Control inputs
HWG THERMOSTAT /
SENSOR
ENABLING DEVICE
LOUVER PROVING SWITCH
SYSTEM SENSOR -
SUPPLY
SYSTEM SENSOR -
RETURN
Service Manual
CASCADE
LOW VOLTAGE
CONNECTION
BOARD
OUTDOOR SENSOR
SEQUENCER / BUILDING
MANAGMENT SYSTEM
AUX SWITCH 1 & 2
0-10 INPUT FROM
SYSTEM PUMP
INLET TEMPERATURE
SENSOR
OUTLET TEMPERATURE /
HI-LIMIT SENSOR
FLUE GAS SENSOR
INLET AIR SENSORS
AIR PRESSURE SWITCH
MANUAL RESET
HIGH LIMIT
FLAME SENSOR 1 & 2
BLOCKED DRAIN SWITCH
MODBUS
BOARD
SMART CONTROL
MODULE
GAS PRESSURE SWITCHES
LOW WATER CUTOFF
BLOWER PROVING
SWITCHES
VENT DAMPER
PROVING SWITCH
8
DISPLAY PANEL
PC INTERFACE
1 Service
1 Service (continued)
Control outputs
LOW VOLTAGE
CONNECTION
BOARD
LINE VOLTAGE
NL
FIELD SUPPLIED CONTACTOR MUST
BE INSTALLED
TERMINAL
SUPPLY
120V
SYSTEM PUMP BOILER PUMP DHW PUMP
MAX. 1.5 AMPS PER CONNECTION
STRIP
Service Manual
0-10V OUTPUT TO
BOILER PUMP
ALARM CONTACTS
LOUVER RELAY
RUN TIME CONTACTS
BOILER RATE OUTPUT
SEQUENCER / BUILDING
MANAGMENT SYSTEM
SMART CONTROL
MODULE
BOILER PUMP
CONTACTOR
SYSTEM PUMP
CONTACTOR
HWG PUMP
CONTACTOR
IGNITOR
BLOWERS
GAS VALVES
VENT DAMPER
DISPLAY PANEL
PC INTERFACE
9
1 Service
Service Manual
General Operation
How the boiler operates
The Crest uses an advanced stainless steel heat exchanger
and electronic control module that allows fully condensing
operation. The blowers pull in air and push flue products out
of the boiler through the heat exchanger and flue piping. The
control module regulates blower speeds to control the boiler
firing rate. The gas valves sense the amount of air flowing into
the boiler and allow only the right amount of gas to flow.
How the control modules operate
The Crest boiler is equipped with a SMART TOUCH control
module. The SMART TOUCH control module receives inputs
from boiler sensors and external devices. The control module
activates and controls the blowers and gas valves to regulate heat
input and switches the boiler, Hot Water Generator (HWG),
and system pumps on and off as needed. The user programs
the control module to meet system needs by adjusting control
parameters. These parameters set operating temperatures and
boiler operating modes.
Sequence of operation
Figure 1-1 Home Screen
Figure 1-2 Main Menu Screen
Table 1A (page 12) shows control module normal sequences of
operation for space heating and HWG operation. The combined
operation sequence is for a typical application, programmed to
provide HWG priority.
Access modes
User
The USER can adjust various space heating and HWG operating
variables:
- Navigate to the Initial Setup Screen (FIG. 1-5).
- From the Home Screen (FIG. 1-1), press MAIN
MENU, then press SETUP on the Main Menu
Screen (FIG. 1-2).
- Press ENTER on the Password Screen (FIG. 1-3)
(do not enter any values) and then press INITIAL
SETUP on the Setup Screen (FIG. 1-4).
The USER can set the date and time and adjust temperature set
points, and outdoor reset points.
Under the ADVANCED SETUP menu, the USER can change the
TEMPERATURE UNITS and the LCD BACKLIGHT TIMER.
Figure 1-3 Password Screen
Installer
Most parameters are available only to the INSTALLER, accessible
only by entering the installer password (5309) in the Password
Screen (see the User Section).
10
1 Service (continued)
Service Manual
Figure 1-4 Setup Screen
Figure 1-5 Initial Setup Screen
Saving parameters (reference the Parameter Table -
Table 1B on pages 13 - 17 of this manual)
To adjust and save parameters (reference FIG. 1-5):
To change a parameter, use the arrows next to the parameter
list on the Menu Screen to highlight the desired parameter,
then press SELECT. A short description of the parameter and
its current setting are then displayed on the bottom half of the
screen. To adjust the setting, use the buttons to the left and
right of the current setting.
Note: If the above mentioned buttons to adjust settings do
not appear, the correct PASSWORD has not been entered.
Press the SAVE button after adjusting a parameter value.
Additional parameter settings can then be adjusted or other
navigation buttons can be used to return to previous screens
or the Home Screen (FIG. 1-1).
Note: The SAVE button MUST BE pressed to ensure proper
programming of the control. Failure to press the SAVE
button will require all changes to be reprogrammed.
11
Service Manual
1 Service
Table 1A Sequence of Operation
Sequence of operation
Note: This unit is equipped with two (2) gas train systems. Gas Train 1 will fire first. If the demand cannot be met by the first
gas train, the second gas train (Gas Train 2) will fire.
Upon a call for heat, the control turns on the appropriate pumps (system and boiler pumps for a space heating call,
1.
HW pump for a domestic hot water call).
The control confirms that the low water cutoff contacts are closed and energizes the louvers (optional) and damper
2.
(optional) relays.
The control confirms that the gas pressure switch, blocked drain switch, limits, louver proving switch (optional) and
3.
damper proving switch (optional) contacts close. The Pre-Purge cycle begins.
The control confirms both blowers come up to the desired speed, both blower proving switches close, and the air
4.
pressure switch is closed.
5.
6.
7.
8.
9.
10.
Once the Pre-Purge cycle is complete, the control lowers the blower speeds, initiates sparking of the ignition electrode,
and opens Gas Valve 1.
After a short wait, the control stops sparking and checks for the presence of flame current through the flame sense
electrode.
If the control does not detect flame current, the control will lockout indefinitely, until the RESET button on the touch
screen LCD is pressed. Models FB 1500 - 2500 will have one retry.
If the control detects flame current, the control will hold the blower speed constant for a few seconds to allow the
flame to stabilize, then begin modulating the firing rate in order to maintain the controlling sensor to the desired set
point temperature.
If the current call for heat is for space heating and a HW call for heat becomes active, the control will turn on the HW
pump relay output, then turn off the boiler pump. It will then modulate the blower speed in order to maintain the
outlet temperature to the desired HW outlet set point temperature.
If the first combustion system in the boiler is unable to maintain the desired set point temperature, the second
combustion system in the boiler will be started. Both blowers will modulate to a set speed, and the second gas valve
will be energized. The second combustion system will light from the first combustion system. The second flame will
be monitored much like the first. Once both combustion systems are firing, the control will work in synchronization
to maintain the desired set point temperature. If the heat load should decrease sufficiently, the second combustion
system will be shut down.
11.
12.
13.
14.
12
Once both the space heating and HW calls for heat are satisfied, the control will turn off the gas valve(s) and begin
the Post-Purge cycle. Any pumps that are running will begin their respective Pump Delay cycles.
At the end of the Post-Purge cycle, the louver relay contacts will de-energize.
The control verifies that the blowers stop running and the blower proving switches open.
At the end of the Pump Delay cycle(s), the pump(s) will be turned off.
Service Manual
1 Service
1 Service (continued)
Parameter table
Table 1B This table lists SMART TOUCH control module parameters and where to access them
Menu
INITIAL SETUP
Sub
Item
1Clock18N/AN/AN/AYesYes
2Date18N/AN/AN/AYesYes
3SH Setpoint1832185120YesYes
4HWG Tank Setpoint1832185120YesYes
5MRHL Setpoint1832205205YesYes
6ARHL Setpoint1832200200YesYes
A
7SH Setpoint at Low Outdoor Temp.1932185180YesYes
8SH Setpoint at High Outdoor Temp.193218568YesYes
9Low Outdoor Temperature19-228623YesYes
10High Outdoor Temperature19-228686YesYes
11Boiler Pump Mode24N/AN/AN/ANoYes
12System Pump Mode24N/AN/AN/ANoYes
1SH Min User Setpoint183218532NoYes
2SH Max User Setpoint1832185185NoYes
Parameter Name
(as shown on the LCD screen)
See
Page
Min
Max
Default
UserInstaller
Value ValueValue AccessAccess
3SH Setpoint1832185125YesYes
4SH Offset180369.9NoYes
5SH Differential1807219.8NoYes
6HWG Tank Setpoint1832185120YesYes
7HWG Tank Differential180106.3NoYes
B
8MRHL Setting1832205204.8YesYes
SETPOINTSOUTDOOR RESET
9ARHL Setting1832200199.4YesYes
10HWG Minimum User Setpoint193218560NoYes
11HWG Maximum User Setpoint1932185185NoYes
12HWG Boiler Setpoint1932185180NoYes
13HWG Boiler Offset190369.9NoYes
14HWG Boiler Differential19072185NoYes
1SH Setpoint at Low Outdoor Temp.1932185180YesYes
2SH Setpoint at High Outdoor Temp193218568YesYes
3Low Outdoor Temperature19-228623YesYes
C
4High Outdoor Temperature19-228686YesYes
5Outdoor Air Shutdown193212279.7NoYes
6OA Shutdown Differential203212279.7NoYes
13
Service Manual
1 Service
Parameter table
Table 1B (continued from previous page) This table lists SMART TOUCH control module parameters and where to
access them