45
Part Number
550-110-290/0219
CGt
GAS-FIRED WATER BOILER — Series 2 —
Boiler Manual
12a
Troubleshooting — procedure
Label all wires prior to disconnection when servicing controls.
Wiring errors can cause improper and dangerous operation.
Never jumper (bypass) rollout thermal fuse element or any other
device except for momentary testing as outlined in
Troubleshooting
Charts
. Severe personal injury, death or substantial property damage
can result.
Before troubleshooting:
1. Have the following items:
a. Voltmeter that can check 120VAC and 24VAC.
b. Microammeter with a minimum scale range of 0-25.
c. Continuity checker.
d. U-tube manometer.
2. Check for 120VAC (minimum 102VAC to maximum 132VAC) to boiler.
3. Make sure thermostat is calling for heat and contacts (including appropriate zone
controls) are closed. Check for 24VAC between thermostat wire nuts and ground.
Check the following:
1. Wire connectors to control module are securely plugged in at module and originating
control.
2. Air pressure switch hoses are properly and securely plugged in and are not damaged.
3. Gas pressures:
a. With boiler off — 13” w.c. maximum natural or propane gas pressure upstream
of gas valve.
b. With boiler on:
• 5” w.c. minimum natural gas pressure or 11” w.c. propane gas pressure
upstream of gas valve.
• 3 ½” w.c. minimum natural gas pressure or 10” w.c. propane gas pressure
downstream of gas valve — Can be adjusted by regulator on gas valve.