Weil-McLain CGS-4E Boiler User Manual


 
Part number 550-110-282/1108
48
GOLD
CGs-4E Gas-Fired Water Boiler — Boiler Manual
Troubleshooting — control module lights11d
Electrical shock hazard — Wherever you see TURN OFF POWER, follow the instructions. Failure to follow
instructions could result in severe personal injury, death or substantial property damage.
CHART 2 TSTAT CIRC & POWER lights flashing
No Yes
Did you find a voltage across the two external thermostat circuit wires?
NoYes
Leave external boiler thermostat connection wires
disconnected from boiler.
Troubleshoot the external thermostat circuit until you find
the source of the stray voltage. (Pay close attention to
the wiring connections to 3-wire zone valves.)
Correct the problem and repeat the voltmeter test above,
verifying there is no longer a voltage reading under any
condition in the external thermostat circuit.
An isolating relay may be required.
Disconnect the two external wires connected to the boiler
thermostat leads (two black low voltage leads in J-box).
Connect a voltmeter across these two incoming wires.
Close each thermostat, zone valve and relay in the external
circuit one at a time and check the voltmeter reading
across the wires.
There should NEVER be a voltage reading.
If a voltage does occur under any condition, check and
correct the external wiring. (This is a common problem
when using 3-wire zone valves.)
Once the external thermostat circuit wiring is checked and
corrected if necessary, reconnect the external thermostat
circuit wires to the boiler thermostat wires and allow the
boiler to cycle.
Boiler should now operate per the normal sequence of
operation shown in Figure 18, page 33.
If no voltage is found under any condition of the external
thermostat circuit, connect the two boiler thermostat
connection leads together (or jumper the boiler aquastat
T-T terminals).
Turn off power to the boiler for 1 minute.
Turn on power and allow boiler to cycle.
Do the TSTAT and POWER lights still flash?
Replace control module.
Retest.
Usually indicates 48 VAC on thermostat circuit (stray voltage) —