Truma 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.
How to read the code
Confirm whether you are on gas or electric, check for a tripped reset, and note any status-light pattern before resetting power.
All documented codes
E1 warning
No flame detected. The AquaGo attempted to ignite the gas burner three times and could not… E202H warning
Combi cold-weather gas fault: the gas-pressure regulation system has iced up so gas cannot… E211H / E212H warning
Gas-supply / combustion fault group on the Combi: the burner could not run because gas is … W17H warning
Hot-water mode was selected while the water heater (boiler) is empty. The unit reports the… W21H warning
Room-temperature sensor warning on the Combi: the CP plus has detected that the room tempe… W27 warning
Water circulation pump running dry. The internal circulation pump is not detecting adequat… W29 info
Excessive heat demand. The unit is running at full capacity but cannot maintain the target… W30 warning
Risk of freezing. The temperature inside the AquaGo has fallen below roughly 27 F (about m… W31 info
Decalcification finished. A status message confirming the unit has completed its routine d… W42H warning
Roof-window safety warning on the Combi: a window above the heater's exhaust cowl is open … W45H warning
Electric (230 V) heating warning on Combi E models: the heater is set to use the 230 V AC … W255H warning
Communication/power warning: the heater is not receiving 12 V DC power, or the CP plus con…
No flame detected. The AquaGo attempted to ignite the gas burner three times and could not… E202H warning
Combi cold-weather gas fault: the gas-pressure regulation system has iced up so gas cannot… E211H / E212H warning
Gas-supply / combustion fault group on the Combi: the burner could not run because gas is … W17H warning
Hot-water mode was selected while the water heater (boiler) is empty. The unit reports the… W21H warning
Room-temperature sensor warning on the Combi: the CP plus has detected that the room tempe… W27 warning
Water circulation pump running dry. The internal circulation pump is not detecting adequat… W29 info
Excessive heat demand. The unit is running at full capacity but cannot maintain the target… W30 warning
Risk of freezing. The temperature inside the AquaGo has fallen below roughly 27 F (about m… W31 info
Decalcification finished. A status message confirming the unit has completed its routine d… W42H warning
Roof-window safety warning on the Combi: a window above the heater's exhaust cowl is open … W45H warning
Electric (230 V) heating warning on Combi E models: the heater is set to use the 230 V AC … W255H warning
Communication/power warning: the heater is not receiving 12 V DC power, or the CP plus con…