Weil-McLain Series 2 Manual page 99

® S
ERIES
Troubleshooting
Figure 106 Troubleshooting suggestions for ECO boilers — Fault displays, diagnostics and corrective actions
Condition
Display
Control is not receiving
Nothing shown
24V power
on display
screen and
boiler will not
respond to call
for heat
Control is not receiving
Nothing
120V power
is shown
in display
screen and no
other boiler
components are
operating
Occurs if the
Nothing is
communication is lost from
shown on
the control module to the
display screen,
display.
but boiler is
operating
Occurs if supply water
TEMP RISE TOO
temperature in heat
QUICKLY
exchanger rises faster than
2°F per second during the
first two minutes the burner
is on.
Boiler Out temperature
SUPPLY 58º F >
has exceeded the Boiler In
RETURN
temperature by more than
58°F
Occurs if a return water
RETURN >
temperature is greater than
SUPPLY
the corresponding supply
temperature by 10°F or
more.
Part number 550-142-190/1218
2
-
G
AS FIRED WATER BOILER
(continued)
Diagnostics
Check wiring for short circuit or
incorrect wiring.
Check 3-amp low voltage fuse
on control module shown on
page 96.
Check transformer connection
to the control module per wiring
diagram. Check for 24V output of
transformer.
Check service switch and/or
circuit breaker to ensure boiler is
turned on.
Is there 120 Volts at the service
switch?
Check for 120 volts at the line
voltage terminal block located at
P1 on the control module.
Inspect 12-amp fuse as shown on
page 96. Replace if necessary.
Check for loose connections
and proper pin alignment/
engagement on the control
module's plug P9 and the back of
the display circuit board.
Cycle power off and on using
service switch or breaker.
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.
Automatically resets after 30
second delay or using manual
reset on display.
Automatically resets when
condition no longer exists.
— Boiler Manual
Corrective Action(s)
Correct wiring per wiring diagram including connection of transformer
to the control module.
Replace fuse with proper part found in replacement part section of this
manual. If fuse blows again recheck wiring per diagram.
Replace transformer if it is receiving 120VAC, but not outputting 24VAC.
Turn on service switch to power boiler.
Troubleshoot and correct the power supply to the service switch.
Correct wiring to the control module using the wiring diagram in this
manual.
Replace the fuse with proper part found in the replacement part section
of this manual. If fuse blows again recheck wiring per diagram.
Check for continuity on the wire harness from the display to the control
module. See repair parts section for proper replacement part.
Replace with new display module. See repair parts section for proper
replacement part.
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.
See message displayed TEMPERATURE SENSOR and follow procedure for
loose connections.
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.
See message displayed TEMPERATURE SENSOR and follow procedure for
loose connections.
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.
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