Way Valve - Weil-McLain GOLD CGt Manual

GOLD CGt Gas-Fired Water Boiler — Boiler Manual
11b
Troubleshooting — components
Control module
Solder or water
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.
Make sure
wiring diagram. Good grounding is
extremely important for proper operation.
Figure 34 Control module
Control indicator lights —
lockout modes
See through in this section for detailed troubleshooting
Charts 1 7
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 or call for heat.
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.
Part Number 550-110-290/0501
splatter between plugs and
is installed per
ground wiring
071039
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 —
non-lockout modes
FLAME light flashing alone
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.
PRESS SWITCH light flashing alone
Usually indicates pressure switch opened during the run cycle.
Troubleshooting the control module
See , page 46, for location of harness plug receptacles
Figure 35
and plugs on the 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 during 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 operation 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 position.
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.
(continued)
45