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.
Alde
Gas failure
The boiler tried to ignite the LPG burner but did not establish a flame, or it r… Low battery
The 12V supply to the boiler has dropped below about 10.5V, which can cause a sy… Overheat (red fail)
The overheat protection on the red cable has tripped. The boiler reached an over… Overheat PCB
The boiler's circuit board (PCB) failsafe over-temperature protection has trigge…
The boiler tried to ignite the LPG burner but did not establish a flame, or it r… Low battery
The 12V supply to the boiler has dropped below about 10.5V, which can cause a sy… Overheat (red fail)
The overheat protection on the red cable has tripped. The boiler reached an over… Overheat PCB
The boiler's circuit board (PCB) failsafe over-temperature protection has trigge…
Aqua-Hot
Fault Code 0 (1 blink)
The diesel-burner indicator light is not lit even though the diesel-burner switc… Fault Code 1
Low supply voltage detected by the diesel-burner controller. The 12V supply is b… Fault Code 8
The burner failed to ignite on its initial start attempt, or the right high-limi… Fault Code 9
Re-ignition failure. The burner lit and established a flame, the flame then went…
The diesel-burner indicator light is not lit even though the diesel-burner switc… Fault Code 1
Low supply voltage detected by the diesel-burner controller. The 12V supply is b… Fault Code 8
The burner failed to ignite on its initial start attempt, or the right high-limi… Fault Code 9
Re-ignition failure. The burner lit and established a flame, the flame then went…
Atwood
1 flash
One LED flash followed by a 3-second pause, repeating. Indicates a limit switch … 2 flashes
Two LED flashes followed by a 3-second pause, repeating. Indicates a flame sense… 3 flashes
Three LED flashes followed by a 3-second pause, repeating. Indicates an ignition… 4 flashes
On a 2-stage Excalibur furnace control board, four flashes of the diagnostic LED… 5 flashes
On a 2-stage Excalibur furnace control board, five flashes indicate a module (co… Steady on (no flash)
The diagnostic LED on the ignition control board is on continuously with no flas…
One LED flash followed by a 3-second pause, repeating. Indicates a limit switch … 2 flashes
Two LED flashes followed by a 3-second pause, repeating. Indicates a flame sense… 3 flashes
Three LED flashes followed by a 3-second pause, repeating. Indicates an ignition… 4 flashes
On a 2-stage Excalibur furnace control board, four flashes of the diagnostic LED… 5 flashes
On a 2-stage Excalibur furnace control board, five flashes indicate a module (co… Steady on (no flash)
The diagnostic LED on the ignition control board is on continuously with no flas…
Chinese Diesel Heater
E1
Most commonly under-voltage: the heater senses supply voltage below the safe ope… E2
Most commonly over-voltage: the supply voltage is above the safe limit and the h… E3
On the widely-sold Vevor-style controllers E03 indicates a glow plug (ignition p… E4
On Vevor-style controllers E04 indicates a fuel pump fault (pump disconnected or… E5
On Vevor-style controllers E05 is an over-heat (over-temperature) protection tri… E6
On Vevor-style controllers E06 indicates a fan / blower motor fault (the combust… E7
On Vevor-style controllers E07 is a communication / broken-circuit error between… E8
On Vevor-style controllers E08 is a flame-out / low-fuel fault — the flame faile… E9
Commonly a glow plug / ignition-circuit electrical fault: the glow plug circuit … E10
Two documented meanings: (1) repeated start-up failure — the heater has tried an… E11
Glow plug / heating-element performance fault: the plug is electrically connecte…
Most commonly under-voltage: the heater senses supply voltage below the safe ope… E2
Most commonly over-voltage: the supply voltage is above the safe limit and the h… E3
On the widely-sold Vevor-style controllers E03 indicates a glow plug (ignition p… E4
On Vevor-style controllers E04 indicates a fuel pump fault (pump disconnected or… E5
On Vevor-style controllers E05 is an over-heat (over-temperature) protection tri… E6
On Vevor-style controllers E06 indicates a fan / blower motor fault (the combust… E7
On Vevor-style controllers E07 is a communication / broken-circuit error between… E8
On Vevor-style controllers E08 is a flame-out / low-fuel fault — the flame faile… E9
Commonly a glow plug / ignition-circuit electrical fault: the glow plug circuit … E10
Two documented meanings: (1) repeated start-up failure — the heater has tried an… E11
Glow plug / heating-element performance fault: the plug is electrically connecte…
Espar (Eberspächer)
012
Overheating detected by software: the outlet (heat-exchanger) temperature exceed… 017
Overheat shutdown. The temperature measured at the overheat sensor has exceeded … 019
Glow plug (glow pin) energy too low: the glow plug is not delivering enough heat… 020 / 021 / 022
Glow plug electrical fault: 020 = open circuit / interruption (broken plug or di… 047 / 048
Metering (fuel dosing) pump fault: 047 = short circuit / overload on the pump ou… 050
Operating lockout: too many unsuccessful start attempts. After repeated failed s… 052
Unsuccessful start (no flame established). The heater attempted to start but did… 053 / 054 / 055 / 056
Flame-out (flame cut-out) during operation: a stable flame was established but t…
Overheating detected by software: the outlet (heat-exchanger) temperature exceed… 017
Overheat shutdown. The temperature measured at the overheat sensor has exceeded … 019
Glow plug (glow pin) energy too low: the glow plug is not delivering enough heat… 020 / 021 / 022
Glow plug electrical fault: 020 = open circuit / interruption (broken plug or di… 047 / 048
Metering (fuel dosing) pump fault: 047 = short circuit / overload on the pump ou… 050
Operating lockout: too many unsuccessful start attempts. After repeated failed s… 052
Unsuccessful start (no flame established). The heater attempted to start but did… 053 / 054 / 055 / 056
Flame-out (flame cut-out) during operation: a stable flame was established but t…
Suburban
High-limit lockout
The high-temperature limit switch is a normally-closed safety in series with the… Ignition lockout
Suburban NT and SF series RV furnaces do not display a numeric error code or LED… Low-voltage standby
The Fan Control module board continuously monitors supply voltage. On the 12 VDC… Sail switch lockout
On the 12 VDC Fan Control module board, after the thermostat calls for heat the …
The high-temperature limit switch is a normally-closed safety in series with the… Ignition lockout
Suburban NT and SF series RV furnaces do not display a numeric error code or LED… Low-voltage standby
The Fan Control module board continuously monitors supply voltage. On the 12 VDC… Sail switch lockout
On the 12 VDC Fan Control module board, after the thermostat calls for heat the …
Truma
E2H / E16H
VarioHeat ignition/flame fault: the furnace released gas and attempted ignition … E43H
Over-voltage: the supply voltage to the heater is too high (Truma cites above ro… E44H
Under-voltage: the supply voltage to the heater is too low (Truma cites below ro… E112H / E212H
Gas/flame fault group: the burner did not ignite or the flame was not detected, … W18H
Warm-air outlet or circulated-air (return air) intake is blocked, so the unit ca… W25H–W29H
VarioHeat voltage and airflow warnings: W25H = overvoltage above ~16.4 V; W26H =…
VarioHeat ignition/flame fault: the furnace released gas and attempted ignition … E43H
Over-voltage: the supply voltage to the heater is too high (Truma cites above ro… E44H
Under-voltage: the supply voltage to the heater is too low (Truma cites below ro… E112H / E212H
Gas/flame fault group: the burner did not ignite or the flame was not detected, … W18H
Warm-air outlet or circulated-air (return air) intake is blocked, so the unit ca… W25H–W29H
VarioHeat voltage and airflow warnings: W25H = overvoltage above ~16.4 V; W26H =…
Webasto
F00
The heater's control unit (ECU) has an internal fault, the heater has been perma… F01
No start - the heater attempted ignition and, even after a repeated start attemp… F02
Flame abort / flame failure - a flame was established but went out during operat… F03
Supply voltage out of range - the heater's operating voltage was either too low … F04
Premature flame detection - the flame/exhaust temperature monitor sensed a flame… F07
Fuel pump fault - the dosing/fuel pump circuit shows an open circuit or short ci… F08
Drive/combustion-air motor fault - the fan motor has an open circuit, short circ… F09
Glow plug / ignition unit fault - the glow plug (or electronic ignition unit) ci… F10
Overheating - the heater exceeded its safe temperature limit and the overheat pr… F14
On the Air Top EVO 40/55: the blow-out (warm-air outlet) temperature sensor circ…
The heater's control unit (ECU) has an internal fault, the heater has been perma… F01
No start - the heater attempted ignition and, even after a repeated start attemp… F02
Flame abort / flame failure - a flame was established but went out during operat… F03
Supply voltage out of range - the heater's operating voltage was either too low … F04
Premature flame detection - the flame/exhaust temperature monitor sensed a flame… F07
Fuel pump fault - the dosing/fuel pump circuit shows an open circuit or short ci… F08
Drive/combustion-air motor fault - the fan motor has an open circuit, short circ… F09
Glow plug / ignition unit fault - the glow plug (or electronic ignition unit) ci… F10
Overheating - the heater exceeded its safe temperature limit and the overheat pr… F14
On the Air Top EVO 40/55: the blow-out (warm-air outlet) temperature sensor circ…