Operating instructions

Part number 550-141-887/0800

AHE Series 4 Direct Vent Wall-Mounted Boilers — Boiler Manual

Make sure boiler water temperature must be 100 °F or

cooler before starting procedure to obtain appropriate

readings.

Check pressure switch setting

1. Remove both air pressure switch hoses from air pressure switch.

2. Install tees and tubing as shown in Figure 27 to inclined manometer.

3. Close the manual main gas valve and set thermostat to call for heat.

Blower will run but main burners will not ignite.

4. Check for 24 VAC between normally open terminal on pressure switch

and ground. See Figure 28.

Troubleshooting air pressure reading

1. If manometer reading is at least 0.55" w.c. pressure, but there is not 24

VAC across normally open terminal on pressure switch and ground,

replace the pressure switch.

2. If manometer reading is lower than 0.55" w.c., look for possible causes:

• blockage in hoses

• obstruction in blower housing outlet

• loose blower wheel on motor shaft

• blower back plate not sealed properly

• blockage in exhaust, air intake pipe or termination.

Return to normal operation

When pressure reading is correct and air pressure switch is operating

properly, remove tees and reinstall tubing to air pressure switch.

Troubleshooting — air pressure switch

12b

Figure 27 Manometer connections Figure 28 Air pressure switch

Red

Pressure switch

Normally

open

Normally

closed

Common

88717

88722

Inclined tube manometer

Blower assembly

to inlet side

To burner

access cover

Suction

Pressure