Weil-McLain GOLD CGt Manual page 47

GOLD CGt Gas-Fired Water Boiler — Boiler Manual
11b
Troubleshooting — components
Control module
Solder or water
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.
Make sure
diagram. Good grounding is extremely important for
proper operation.
Control indicator lights —
LOCKOUT modes
Charts 1
See
shooting procedures.
To reset control after a lockout, turn off power at the 10 VAC
service switch or turn down all thermostats. Wait 45 seconds.
Then restore power or call for heat.
POWER light flashing alone
Usually indicates reversed polarity of 10 VAC power wires.
POWER and TSTAT CIRC lights flashing
Usually indicates stray voltage on external thermostat circuit
wires (usually due to miswired 3-wire zone valve).
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
inducer starting.
POWER and FLAME lights flashing
Usually indicates false flame sense or flame sensed when it
shouldn't be there.
Control indicator lights —
NONLOCKOUT modes
POWER light on and FLAME light flashing
Usually indicates pilot flame was not established within 15
seconds from application of spark. Control will flash light, but
will continue to cycle indefinitely until flame is established or
problem is corrected.
POWER light on and PRESS SWITCH light flashing
Usually indicates pressure switch opened during the run
cycle.
Troubleshooting the control module
Figure 35
See
tacles and plugs on the control module.
Part Number 550-110-290/0107
splatter between plugs and circuit board
ground wiring
is installed per wiring
7
through in this section for detailed trouble-
, page 48,
for location of harness plug recep-
(continued)
Figure 34 Control module
3-Way valve
The 3-way valve redirects flow in the circuit. Normally,
the valve allows water to flow through the boiler and
the heating system. But, if the tankless heater low limit
control senses water temperature below its setting dur-
ing a domestic water demand, the 3-way valve actuator
should change the valve so all flow goes through boiler,
with no flow through heating system. Check valve op-
eration as follows:
Tankless low limit calls for heat, but boiler does not
turn on — Check power to 3-way valve and valve end
switch.
Tankless low limit calls for heat, boiler turns on, but
there is not enough domestic water supply — Check
3-way valve. It may be stuck in the space heating posi-
tion.
Thermostat calls for heat, boiler turns on, but there is no
flow of hot water to the space heating system — Check
whether 3-way valve is stuck in domestic water heating
position. Verify valve is installed and wired correctly.
47