E 112 HGas supply closed or overheat protection active
The burner cannot receive usable fuel, or the appliance has entered overheating protection.
Plain-English answer
Truma groups E 112 H with faults caused by a closed propane cylinder, a closed appliance gas valve, or activated overheating protection.
What to check first
- 01
Confirm the propane cylinder valve and the appliance gas shutoff valve are open.
- 02
Turn the Combi off and allow it to cool completely.
- 03
Fill the water container with cold water and clear blocked warm-air outlets or return-air intakes.
Stop and call a technician when
- If you smell propane, avoid flames and switches, leave the area, and close the supply only if safe.
- Arrange qualified service if the code returns.
Check the exact manual
Applicability: Truma Combi furnace and water-heater systems. The data plate and specification letter determine which procedure is correct.
Open Truma Combi error-code tech tip ↗Source reviewed August 2026Check external controls before further troubleshooting
Follow the manufacturer's checks for your model. Record timing for service, but do not use it alone to distinguish fuel supply from overheating.
Confirm only external gas controls
Check that the cylinder valve and appliance shutoff valve are open. Stop immediately for gas odor; do not loosen fittings, purge indoors, or adjust the regulator.
Cool and restore airflow
Turn the unit off and wait until it is completely cool. Fill the water container with cold water and clear blocked warm-air outlets and circulated-air intakes.
Do not erase repeat evidence
If E112H returns, note the mode, outside temperature, and time to failure. Repeated resets do not identify whether fuel delivery or overheat protection needs service.