Webasto RV furnace fault codes
RV forced-air propane furnaces lock out after failed ignition attempts. Many use a status LED on the control board that flashes a fault pattern.
How to read the code
Find the control board (often behind an exterior access panel or inside under a vent) and watch the status LED. Count the flashes in each group; the pattern maps to a specific fault.
Models covered: every code below applies to the Webasto Air Top 2000 STC, Air Top EVO 40, Air Top EVO 40 B, Air Top EVO 40 D, Air Top EVO 55.
All documented codes
F00 warning
The heater's control unit (ECU) has an internal fault, the heater has been permanently loc… F01 warning
No start - the heater attempted ignition and, even after a repeated start attempt, no flam… F02 warning
Flame abort / flame failure - a flame was established but went out during operation and di… F03 warning
Supply voltage out of range - the heater's operating voltage was either too low or too hig… F04 warning
Premature flame detection - the flame/exhaust temperature monitor sensed a flame before co… F07 warning
Fuel pump fault - the dosing/fuel pump circuit shows an open circuit or short circuit, so … F08 warning
Drive/combustion-air motor fault - the fan motor has an open circuit, short circuit, overl… F09 warning
Glow plug / ignition unit fault - the glow plug (or electronic ignition unit) circuit show… F10 danger
Overheating - the heater exceeded its safe temperature limit and the overheat protection t… F14 warning
On the Air Top EVO 40/55: the blow-out (warm-air outlet) temperature sensor circuit has a …
The heater's control unit (ECU) has an internal fault, the heater has been permanently loc… F01 warning
No start - the heater attempted ignition and, even after a repeated start attempt, no flam… F02 warning
Flame abort / flame failure - a flame was established but went out during operation and di… F03 warning
Supply voltage out of range - the heater's operating voltage was either too low or too hig… F04 warning
Premature flame detection - the flame/exhaust temperature monitor sensed a flame before co… F07 warning
Fuel pump fault - the dosing/fuel pump circuit shows an open circuit or short circuit, so … F08 warning
Drive/combustion-air motor fault - the fan motor has an open circuit, short circuit, overl… F09 warning
Glow plug / ignition unit fault - the glow plug (or electronic ignition unit) circuit show… F10 danger
Overheating - the heater exceeded its safe temperature limit and the overheat protection t… F14 warning
On the Air Top EVO 40/55: the blow-out (warm-air outlet) temperature sensor circuit has a …