Furrion E4 fault code — Water heater
Applies to: FWH09A-AM, FWH09AFA, FWH09AFA-AM, FWH09AFA-AB
What E4 means
The Furrion tankless water heater troubleshooting manual lists E4 as Water inlet temperature system fault.
Owner-safe checks
- Turn the water heater off.
- Contact Furrion if the code continues after a normal reset.
Service-only work
- Flame sensing, combustion, air pressure, fan, solenoid, sensor, board, LP, exhaust, and internal water-heater diagnosis is qualified service work.
Safety boundary
Do not run a gas water heater with abnormal flame, blocked venting, gas odor, or repeated lockout. Shut off LP/power and call service if the code persists.