Espar (Eberspächer) Furnace: “053 / 054 / 055 / 056”
warning RV furnace fault codes
What it means
Flame-out (flame cut-out) during operation: a stable flame was established but then lost during running, grouped by the power stage at which it failed (053 = lower power range up through 056 = full power / from start). The heater shuts down because the flame sensor no longer detects combustion.
Most likely causes
- Running low on fuel or intermittent fuel delivery (air in line, clogging filter) most likely
- Restricted combustion-air intake or partially blocked exhaust common
- Carbon build-up in the burner / worn glow plug screen common
- Weak metering pump or flame sensor reading low less common
Safe checks you can do yourself
- Check fuel level and that the pickup still draws fuel as the tank empties.
- Inspect combustion-air intake and exhaust for obstruction.
- Check/clean or replace the fuel filter if accessible.
- Run the heater and note at which output level it cuts out.
How to reset / clear 053 / 054 / 055 / 056
- Switch the heater off and on to restart.
- If flame-out repeats and the unit locks out, clear the lockout with a diagnostic tool after correcting the fuel/air issue.
When to call a technician
If flame-out continues after fuel filter, fuel supply, air intake and exhaust are confirmed good, or if the metering pump or flame sensor is suspected.
Applies to
Airtronic D2 · Airtronic D4 · Airtronic D4S · Airtronic B4
FAQ
What does Espar (Eberspächer) Furnace code "053 / 054 / 055 / 056" mean?
Flame-out (flame cut-out) during operation: a stable flame was established but then lost during running, grouped by the power stage at which it failed (053 = lower power range up through 056 = full power / from start). The heater shuts down because the flame sensor no longer detects combustion.
How do I reset Espar (Eberspächer) Furnace 053 / 054 / 055 / 056?
Switch the heater off and on to restart. If flame-out repeats and the unit locks out, clear the lockout with a diagnostic tool after correcting the fuel/air issue.
What is the most common cause of 053 / 054 / 055 / 056 on a Espar (Eberspächer) Furnace?
The most likely cause is running low on fuel or intermittent fuel delivery (air in line, clogging filter).
Related · Espar (Eberspächer) furnace
Overheating detected by software: the outlet (heat-exchanger… 017
Overheat shutdown. The temperature measured at the overheat … 019
Glow plug (glow pin) energy too low: the glow plug is not de… 020 / 021 / 022
Glow plug electrical fault: 020 = open circuit / interruptio… 047 / 048
Metering (fuel dosing) pump fault: 047 = short circuit / ove… 050
Operating lockout: too many unsuccessful start attempts. Aft…
Sources
- Eberspacher Airtronic Fault Codes — Codes 53-56, flame cutout during various power stages (Le Tonkinois (independent Eberspacher reference))
- Find and clear Espar Airtronic fault codes and Eberspacher Hydronic fault codes — Flame cutout events, P000125-P000128 (057/053/054/055) by power range (Heatso)
Note: Exact power-band-to-number mapping varies slightly between firmware/sources (e.g. 057 also appears for the 0-25% band on newer units). The grouped meaning (flame-out by power stage) is consistent.
● Last verified 2026-06-29 · compiled from manufacturer documentation. Codes can vary by model year — always cross-check your unit’s manual.