GOLD CGs
11d Troubleshooting — control module lights
CHART 2 — TSTAT CIRC & POWER lights flashing
— Usually indicates 48 VAC on thermostat circuit (stray voltage) —
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.
•Disconnect the two external wires connected to the boiler thermostat leads (two black low voltage leads in
•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
•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.
Did you find a voltage across the two external thermostat circuit wires?
Yes
No
•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
•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.
•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
• 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?
No |
| Yes | |
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•Boiler should now operate per the normal sequence of operation shown in Figure 18, page 31.
•Replace control module.
•Retest.
46 | Part number |
