GOLD CGs 
11b Troubleshooting — air pressure switch
Air pressure switch
Make sure boiler water temperature is 100 °F or cooler before starting procedure to obtain appropriate readings.
Check pressure switch setting
1.See Figure 24 and Table 6.
2.Remove both air pressure switch hoses from air pressure switch.
3.Install tees and tubing as shown in Figure 24 to inclined manometer.
4.Turn off gas valve and set thermostat to call for heat. Inducer will run but burners will not ignite.
5.Check for 24 VAC between both air pressure switch terminals and ground.
6.If manometer reading is above the setpoint of the switch (see Table 6), but there is not 24 VAC between both air pressure switch terminals and ground
— replace air pressure switch.
Figure 24 Manometer connections
Table 6 | Pressure switch setpoint | |
| (for elevations above 2,000 ft, contact your | |
| local | |
|
| |
Boiler model number | Inches W.C. | |
| 1.79" | |
|
|
|
| 1.48" | |
| 1.22" | |
|
|
|
| 0.95" | |
|
|
|
Troubleshooting air pressure reading
1.If manometer reading is lower than the setpoint of the switch (see Table 6) — 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
•blockage in flue pipe or termination
•incorrect 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.
The boiler will not operate cor- rectly unless pressure switch hoses are correctly located. The red hose connects 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 24.
44 | Part number |
