P2030
Fuel Fired Heater Performance
The fuel-fired auxiliary heater is operating but not delivering the expected heat output within the calibrated time — flame sensor reports weak combustion, exhaust temperature does not rise, or coolant heating rate is below threshold.
- Check engine light: Not always
- Emissions related: No
- Repair difficulty: medium
Common causes
Ordered by how often each turns out to be the cause.
- Combustion chamber sooted from short cyclesCommon
- Flame sensor degradedPossible
Parts involved
- Fuel Fired Heater
- Heater Flame Sensor
- Heater Combustion Chamber
P2030 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.