Furrion fwh09
What it is
Furrion FWH09 (2.4 GPM class), about 60,000 BTU. Gas inlet about 11 to 14 in W.C. Water pressure about 7.2 to 65 PSI. Minimum flow about 0.32 GPM. Temperature about 95 to 124 F. 10 A fuses.
Reset
Turn the heater power switch OFF for 5 seconds, then ON. Write the code down first.
Older Furrion F2GWH units use Girard-style code meanings. This table is for the FWH09 and codes DO differ. Check the model label.
Fault codes
E0|Outlet temperature fault|Reseat and measure the outlet sensor. Replace if open or shorted. Check the connector for water.
E1|No flame sensed at ignition|Gas supply, valves, regulator pressure under load, tank level, igniter and flame sensor condition, air in the line after a tank change.
E2|False flame sensed|A stuck gas valve or a shorted flame sensor. Gas valve problems need a service replacement. Check wiring first.
E3|Overtemperature sensor|Run cold water through for 10 to 20 seconds, then restart. If it returns, check the sensor and thermistors.
E4|Inlet temperature sensor fault|Reseat and measure the inlet sensor. Replace if open or shorted.
E5|Air pressure fault|Exhaust or intake blocked, wind pushing into the vent, a cracked hose, or a failing pressure switch. Clear the vent first.
E6|Temperature surge|Cold-water surge, crossover between hot and cold, low flow, air in the lines, or a plugged inlet filter. Check plumbing and mixing valves.
E7|Solenoid fault|Check the solenoid plug and coil resistance. Replace the valve assembly if open.
Quick checks
10 A fuses good
12V at the board under load
Inlet gas pressure while firing
Hot and cold not reversed
Inlet filter screen clean
Vent and intake clear
E6 plus a hot-then-cold complaint almost always means plumbing: a mixing valve, crossover or low flow.