Your RV threw a code. Let's decode it.
Search by brand, model, error code, or symptom. Get the likely meaning, the safe first checks, and a clear line between DIY and calling a pro.
Featured fault guides
Combustion air, gas, overheat, or electronics fault
The Combi may be missing combustion air, fuel, or power, and unresolved cases can indicate an electronics defect.
TrumaFull guide →W 45 HCheck AC power120-volt supply missing or overheat protection active
Applicable plus models either lack AC power or have activated overheating protection.
TrumaFull guide →E 112 HCheck gas supplyGas supply closed or overheat protection active
The burner cannot receive usable fuel, or the appliance has entered overheating protection.
TrumaFull guide →W 18 HClear airflowWarm-air outlet or circulated-air intake blocked
The heater cannot move enough air because an outlet or return-air opening is obstructed.
TrumaFull guide →Code 36Check firstEngine stopped without a command
The controller recorded an unexpected engine shutdown. Fuel supply is a practical first check, but the code is not a diagnosis by itself.
Cummins OnanFull guide →no coService advisedNo cooling detected
The cooling unit did not produce the expected temperature drop. A second occurrence is not owner-serviceable.
NorcoldFull guide →Browse all 65 fault guides → · Troubleshooting without a code →
Start with what stopped working.
A useful answer in three moves.
Match the appliance model and exact code before touching anything.
See what the fault means, how urgent it is, and what commonly triggers it.
Follow owner-safe checks or stop at the point that needs a qualified technician.