Control Module Troubles - Weil-McLain Gold GV Manual

XIe
Troubleshooting — control module
Control Module
Make sure
Good grounding is extremely important for proper
operation.
Control indicator lights —
lockout modes
See Charts 1 through 8 in this section for detailed trouble-
shooting procedures.
To reset control after a lockout, turn off power at the 120
VAC service switch or turn down all thermostats. Wait 45
seconds. Then restore power and call for heat.
After an over-temperature lockout (
lights flashing), the control will only reset after
interruption of 120 VAC for 45 seconds. (And
temperature at return water temperature sensor must
be below 240 °F.)
POWER light flashing alone
Usually indicates reversed polarity of 120 VAC power
wires.
POWER and TSTAT CIRC lights flashing
Usually indicates stray voltage on external thermostat
circuit wires or return water temperature entering
boiler sections has not reached 140 °F within 20
minutes.
POWER and LIMIT light flashing alternately
Usually indicates that limit circuit failed to cut off boiler
at high temperature — return water temperature sensor
has sensed water over 235 °F.
POWER and PRESS SWITCH lights flashing
Usually indicates pressure switch is closed when it
should not be, or pressure switch failed to close within
5 minutes of blower starting.
POWER and FLAME lights flashing
Usually indicates control has had three unsuccessful
70
GOLD GV W GOLD GV W
GOLD GV Water Boiler — Series 4 GOLD GV W GOLD GV W
is installed per wiring diagram.
ground wiring
splatter between
Solder or water
plugs and circuit board can cause
improper operation of control
module. Place a shield over the
boiler internal controls and
components during installation.
Failure to comply could result in
severe personal injury, death or
substantial property damage.
POWER
ater Boiler — Series 4 ater Boiler — Series 4
ater Boiler — Series 4 ater Boiler — Series 4
and LIMIT
ignition attempts or sensed flame when it shouldn't be
there. Boiler may not be properly grounded.
Non-lockout light conditions
TSTAT CIRC light flashing alone
Usually indicates return water temperature sensor detects
water at boiler return pipe less than 40 °F. Both internal
circulators will run continuously, even with no call for
heat, until temperature rises.
LIMIT light flashing alone
Usually indicates an open or shorted return water
temperature sensor.
Troubleshooting the GCM
See Figure 34 for location of harness plug receptacles
and plugs on the control module.
Part number 550-141-856/0703