Truma Furnace: “E44H”
warning RV furnace fault codes
What it means
Under-voltage: the supply voltage to the heater is too low (Truma cites below roughly 10.0 V on CP plus / below ~10.5 V on older units). The heater cannot operate reliably and stops.
Most likely causes
- Leisure/house battery discharged or weak and unable to hold charge most likely
- Poor or corroded battery / ground connection causing voltage drop common
- Undersized wiring or high load dragging voltage down while the fan runs less common
Safe checks you can do yourself
- Measure battery voltage; charge the battery and retest
- Inspect battery terminals and the heater's negative/ground connection for corrosion or looseness
- Try running the heater with the engine running or on shore-charge to confirm low battery is the cause
How to reset / clear E44H
- Charge or replace the battery so supply voltage is back in range — the fault usually clears automatically
- On CP plus, if it persists, press and hold / double-click the displayed code and back out to acknowledge it
When to call a technician
If the battery is good and connections are clean but the under-voltage code remains, have the wiring and heater electronics checked.
Applies to
Combi 4 · Combi 6 · Combi 4 E · Combi 6 E · Combi Eco Plus · Combi Comfort Plus
FAQ
What does Truma Furnace code "E44H" mean?
Under-voltage: the supply voltage to the heater is too low (Truma cites below roughly 10.0 V on CP plus / below ~10.5 V on older units). The heater cannot operate reliably and stops.
How do I reset Truma Furnace E44H?
Charge or replace the battery so supply voltage is back in range — the fault usually clears automatically On CP plus, if it persists, press and hold / double-click the displayed code and back out to acknowledge it
What is the most common cause of E44H on a Truma Furnace?
The most likely cause is leisure/house battery discharged or weak and unable to hold charge.
Related · Truma furnace
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VarioHeat voltage and airflow warnings: W25H = overvoltage a…
Sources
- Tech Tip: Truma Combi Error Codes — Truma Combi error code reference, E44H (Truma (official US site))
- List of flash codes Combi 4 (E) / 6 (E) — Fault no. 44, under voltage lower than 10.5 V (Truma (OEM flash-code list via Dometic RV Centre))
Note: Threshold differs slightly between CP plus (~10.0 V) and older list (~10.5 V); both confirm 'under-voltage'.
● Last verified 2026-06-29 · compiled from manufacturer documentation. Codes can vary by model year — always cross-check your unit’s manual.