Install Instructions

Troubleshooting (continued)
Display
Condition Diagnostics Corrective Action(s)
Nothing shown
on display
screen and
boiler will not
respond to call
for heat
Control is not receiving
24V power
Check wiring for short circuit or
incorrect wiring.
Correct wiring per wiring diagram including connection of transformer
to the control module.
Check 3-amp low voltage fuse
on control module shown on
QBHF.
Replace fuse with proper part found in replacement part section of this
manual. If fuse blows again recheck wiring per diagram.
Check transformer connection
to the control module per wiring
diagram. Check for 24V output of
transformer.
Replace transformer if it is receiving 120Vac, but not outputting 24Vac.
Nothing
is shown
in display
screen and no
other boiler
components are
operating
Control is not receiving
120V power
Check service switch and/or
circuit breaker to ensure boiler is
turned on.
Turn on service switch to power boiler.
Is there 120 Volts at the service
switch?
Troubleshoot and correct the power supply to the service switch.
Check for 120 volts at the line
voltage terminal block located at
P1 on the control module.
Correct wiring to the control module using the wiring diagram in this
manual.
Inspect 12-amp fuse as shown on
QBHF. Replace if necessary.
Replace the fuse with proper part found in the replacement part section
of this manual. If fuse blows again recheck wiring per diagram.
Nothing is
shown on
display screen,
but boiler is
operating
Occurs if the
communication is lost from
the control module to the
display.
Check for loose connections
and proper pin alignment/
engagement on the control
NPEVMFhTQMVH1BOEUIFCBDLPG
the display circuit board.
Check for continuity on the wire harness from the display to the control
module. See repair parts section for proper replacement part.
Cycle power off and on using
service switch or breaker.
Replace with new display module. See repair parts section for proper
replacement part.
TEMP RISE TOO
QUICKLY
Occurs if supply water
temperature in heat
exchanger rises faster than
2º F per second during the
first two minutes the burner
is on.
Automatically resets after 1
minute delay or using manual
reset on display.
Manual reset is necessary after 5
automatic resets have occurred
during the same Priority heat
demand. Reset using manual
reset screen on display.
Verify water pipe is installed correctly per instructions in this manual.
Verify proper circulator sizing for boiler size and system requirements.
Verify circulator connected to correct circulator output on the control
module’s plug P2.
Verify external controls are installed per manufacturer’s instructions, all
applicable codes, and sound industry practices.
4FFNFTTBHFEJTQMBZFE5&.1&3"563&4&/403BOEGPMMPXQSPDFEVSFGPS
loose connections.
SUPPLY 58º F >
RETURN
Boiler Out temperature
has exceeded the Boiler In
temperature by more than
58º F
Automatically resets after 30
second delay or using manual
reset on display.
Verify water pipe is installed correctly per instructions in this manual.
Verify proper circulator sizing for boiler size and system requirements.
Verify circulator connected to correct circulator output on the control
module’s plug P2.
Verify external controls are installed per manufacturer’s instructions, all
applicable codes, and sound industry practices.
4FFNFTTBHFEJTQMBZFE5&.1&3"563&4&/403BOEGPMMPXQSPDFEVSFGPS
loose connections.
RETURN >
SUPPLY
Occurs if a return water
temperature is greater than
the corresponding supply
temperature by 10º F or
more.
Automatically resets when
condition no longer exists.
Verify proper flow direction of the boiler or system circulator. This
circulator must be installed to push water through the boiler’s return
pipe as shown in piping diagrams beginning on .
Verify circulator connected to correct circulator output on the control
module’s plug P2.
Verify external controls are installed per manufacturer’s instructions, all
applicable codes, and sound industry practices.
&IGURE Troubleshooting suggestions for %#/ boilers — &AULTDISPLAYSDIAGNOSTICSANDCORRECTIVEACTIONS
Part number 550-142-122/0513
94
TM
GAS-FIRED WATER BOILER — Boiler Manual