Troubleshooting guide

Air Pressure Switch Circuit
Residential Power-Vent & Power-Direct-Vent Water Heaters
Air Pressure Switch Circuit
Cyclone Water Heater
1
4
Blocked Exhaust Switch
Normally Open Contacts
Close on a Fall in Pressure
Vent Temperature Limit Switch
Normally Closed Contacts
Open on a Rise in Temperature
Molex Plug
6 Pin Plug
4
6
Blocked Inlet Switch
Normally Closed Contacts
Open on a Fall in Pressure
Blower Prover Switch
Normally Open Contacts
Close on a Rise in Pressure
Blocked Exhaust Switch
Normally Closed Contacts
Open on a Rise in Pressure
Low Gas Pressure Switch
Normally Open Contacts
Close on a Rise in Pressure
(BTH 120, 250, 300, 400 only)
CN6 Plug
Control Board
AHSA02307 8 of 8