Powertrain, generic (extended)

P2029 Fuel Fired Heater Disabled

Check engine lightUsually off
EmissionsRelevant
Drive cycleNot required
Limp modeNo

A fuel fired heater burns a small amount of the vehicle's fuel to warm coolant or cabin air, a common add-on on diesels with little waste heat. P2029 is a state code: the controller has taken the heater out of service, usually after repeated failed starts, flame-outs, overheating or an electrical fault. CARB counts fuel-fired passenger heaters among other emission sources for which each maker must get its own monitoring plan approved. No manufacturer documents P2029 publicly. Webasto's Air Top Evo shows the pattern: no start, flame loss, overheating and glow plug faults have their own codes, and after too many failures the heater locks out until a workshop releases it. So the real fault, often logged alongside as P2030 or a circuit code, has to be fixed before the lock is cleared. The engine runs normally; the cabin stays cold.

Likely causes

Lock-out after repeated failed starts or flame-outs (fuel supply, glow plug, combustion air)
Heater shut down after overheating, e.g. low coolant flow
Supply voltage too low or wiring fault to the heater

Symptoms

  • Little or no auxiliary heat, slow warm-up
  • Heater does not start when requested
  • Warning lamp depends on the manufacturer

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€50–900
Time0.5–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

fuel fired heaterheater glow plugheater fuel pump

Related codes

P2030

References: law.cornell.edu, dealers.webasto.com, en.wikipedia.org.