RV water heater fault codes
RV water heaters (gas, electric or both) commonly lock out when the burner fails to light. Some boards flash a status light; others simply stop and require a reset.
Atwood
DSI Fault / Lock-Out
On Atwood DSI (Direct Spark Ignition) water heaters there is no multi-digit nume… ECO open / tripped
The ECO is a backup high-limit temperature switch wired in series with the contr… Gas & spark, no flame proven
A diagnostic sub-condition of the DSI lock-out: both gas and spark are present b… Gas present, no spark
A diagnostic sub-condition of the DSI lock-out from the official trouble-shootin… No spark / no ignition
Dead unit with no spark at the electrode and no lockout-light activity, typicall… Spark present, no gas
A diagnostic sub-condition of the DSI lock-out from the official trouble-shootin… TCO (thermal cut-off) tripped
Current Atwood DSI water heaters have a one-shot thermal cut-off device on the i…
On Atwood DSI (Direct Spark Ignition) water heaters there is no multi-digit nume… ECO open / tripped
The ECO is a backup high-limit temperature switch wired in series with the contr… Gas & spark, no flame proven
A diagnostic sub-condition of the DSI lock-out: both gas and spark are present b… Gas present, no spark
A diagnostic sub-condition of the DSI lock-out from the official trouble-shootin… No spark / no ignition
Dead unit with no spark at the electrode and no lockout-light activity, typicall… Spark present, no gas
A diagnostic sub-condition of the DSI lock-out from the official trouble-shootin… TCO (thermal cut-off) tripped
Current Atwood DSI water heaters have a one-shot thermal cut-off device on the i…
Girard
E0
The outlet (hot side) water temperature sensor reads an invalid value. The contr… E1
Ignition failure. The igniter sparked but the board never confirmed a flame, so … E2
Flame sensing was interrupted during normal operation. The burner had lit, but t… E3
The ECO (energy/over-temperature cut-off) thermostat opened, either before ignit… E4
The inlet (cold side) water temperature sensor reads an invalid value while wate… E5
Blower/fan motor fault. The control board commanded the combustion blower to run… E6
Over-temperature condition. The outlet water temperature exceeded the safe limit… E8
Air pressure (vacuum) switch fault. The switch that confirms the blower is movin…
The outlet (hot side) water temperature sensor reads an invalid value. The contr… E1
Ignition failure. The igniter sparked but the board never confirmed a flame, so … E2
Flame sensing was interrupted during normal operation. The burner had lit, but t… E3
The ECO (energy/over-temperature cut-off) thermostat opened, either before ignit… E4
The inlet (cold side) water temperature sensor reads an invalid value while wate… E5
Blower/fan motor fault. The control board commanded the combustion blower to run… E6
Over-temperature condition. The outlet water temperature exceeded the safe limit… E8
Air pressure (vacuum) switch fault. The switch that confirms the blower is movin…
Suburban
DSI lockout
Suburban gas (DSI) water heaters do not show a numeric fault code. When you flip… Electric ECO tripped
On gas/electric (DE) models, the 120V electric heating circuit has its own high-… Electric element no heat
On gas/electric models, the 120V element produces no heat or water is not hot en… Gas ECO tripped
The gas-side ECO (Energy/Electric Cut Off, a high-limit thermostat) on the 12V D… Gas valve won't open
The board is sequencing and spark is present, but the gas valve fails to open so… No reset light
On a DSI SW-series unit, the reset light failing to come on at all when the swit… No spark / no ignition
The control board is powered and attempting to light (reset light cycling) but n…
Suburban gas (DSI) water heaters do not show a numeric fault code. When you flip… Electric ECO tripped
On gas/electric (DE) models, the 120V electric heating circuit has its own high-… Electric element no heat
On gas/electric models, the 120V element produces no heat or water is not hot en… Gas ECO tripped
The gas-side ECO (Energy/Electric Cut Off, a high-limit thermostat) on the 12V D… Gas valve won't open
The board is sequencing and spark is present, but the gas valve fails to open so… No reset light
On a DSI SW-series unit, the reset light failing to come on at all when the swit… No spark / no ignition
The control board is powered and attempting to light (reset light cycling) but n…
Truma
E1
No flame detected. The AquaGo attempted to ignite the gas burner three times and… E202H
Combi cold-weather gas fault: the gas-pressure regulation system has iced up so … E211H / E212H
Gas-supply / combustion fault group on the Combi: the burner could not run becau… W17H
Hot-water mode was selected while the water heater (boiler) is empty. The unit r… W21H
Room-temperature sensor warning on the Combi: the CP plus has detected that the … W27
Water circulation pump running dry. The internal circulation pump is not detecti… W29
Excessive heat demand. The unit is running at full capacity but cannot maintain … W30
Risk of freezing. The temperature inside the AquaGo has fallen below roughly 27 … W31
Decalcification finished. A status message confirming the unit has completed its… W42H
Roof-window safety warning on the Combi: a window above the heater's exhaust cow… W45H
Electric (230 V) heating warning on Combi E models: the heater is set to use the… W255H
Communication/power warning: the heater is not receiving 12 V DC power, or the C…
No flame detected. The AquaGo attempted to ignite the gas burner three times and… E202H
Combi cold-weather gas fault: the gas-pressure regulation system has iced up so … E211H / E212H
Gas-supply / combustion fault group on the Combi: the burner could not run becau… W17H
Hot-water mode was selected while the water heater (boiler) is empty. The unit r… W21H
Room-temperature sensor warning on the Combi: the CP plus has detected that the … W27
Water circulation pump running dry. The internal circulation pump is not detecti… W29
Excessive heat demand. The unit is running at full capacity but cannot maintain … W30
Risk of freezing. The temperature inside the AquaGo has fallen below roughly 27 … W31
Decalcification finished. A status message confirming the unit has completed its… W42H
Roof-window safety warning on the Combi: a window above the heater's exhaust cow… W45H
Electric (230 V) heating warning on Combi E models: the heater is set to use the… W255H
Communication/power warning: the heater is not receiving 12 V DC power, or the C…