GOLD CGi
11a Troubleshooting — procedure
Label all wires prior to disconnection when servicing controls. Wiring errors can cause improper and danger- ous 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 re- sult.
Before troubleshooting:
1.Have the following items:
a.Voltmeter that can check 120 VAC and 24 VAC.
b.Microammeter with a minimum scale range of
c.Continuity checker.
d.
2.Check for 120 VAC (minimum 102 VAC to maximum 132 VAC) to boiler.
3.Make sure thermostat is calling for heat and contacts (including appro- priate zone controls) are closed. Check for 24 VAC between thermostat wire nuts and ground.
Check the following:
1.Wire connectors to control module are se- curely 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 up- stream 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.
11b Troubleshooting — components
Air pressure switch
Make sure boiler water temperature is 100 °F or cooler before starting procedure to obtain appropriate read- ings.
The boiler will not operate correctly unless pressure switch hoses are correctly located. The red hose con- nects from the right side (negative) hose barb to the flue collector. The white hose connects from the left side (positive) hose barb of the switch to the connector box (between flue collector and inducer) as shown in Figure 36, page 49.
Check pressure switch setting
1.See Figure 36, page 49, and Table 9.
2.Remove both air pressure switch hoses from air pressure switch.
3.Install tees and tubing as shown in Figure 36, page 49, to inclined manom- eter.
4.Turn off gas valve and set thermostat to call for heat. Inducer will run but burn- ers will not ignite.
5.Check for 24 VAC between both air pressure switch terminals.
Troubleshooting air pressure reading
1.If manometer reading is lower than the setpoint of the switch (see Table 9)
— check for possible causes:
•blockage in hoses
•obstruction in inducer housing outlet
•loose inducer wheel on motor shaft
•inducer motor not in proper rpm
•inducer back plate not sealed properly
•blockage in block assembly
6.If manometer reading is above the setpoint of the switch (see Table 9), but there is not 24 VAC between both air pressure switch terminals — replace air pressure switch.
Return to normal operation
When pressure reading is correct and air pressure switch is operating properly — remove tees and reinstall hoses to air pressure switch.
Table 9 Pressure switch setpoint (for elevations above 2,000 ft, contact your local Weil- McLain sales office for details.)
48 | Part Number |
|
