E43H

Truma Furnace: “E43H”

warning RV furnace fault codes

Safety Electrical work near 12 V and (on E/Eco Plus models) 120/230 V components carries shock and fire risk. If unsure about charger configuration or wiring, use a qualified technician. Combustion appliance: if you smell gas at any point, stop and ventilate.

What it means

Over-voltage: the supply voltage to the heater is too high (Truma cites above roughly 16.4 V on CP plus / above ~15 V on older units). The electronics shut down to protect themselves.

Most likely causes

Battery charger / converter or solar charge controller pushing voltage too high most likely
Faulty or misconfigured DC power supply or charge source common
Wiring/regulation fault feeding the heater less common

Safe checks you can do yourself

Measure the 12 V supply voltage at the battery with a multimeter and compare against the charger's expected output
Check charger / converter and solar controller settings for an over-voltage condition
Temporarily disconnect a suspected charge source to see if voltage returns to normal range

How to reset / clear E43H

Bring the supply voltage back into the normal range; the fault generally clears on its own
On CP plus, press and hold / double-click the displayed code and back out to acknowledge it if it persists

When to call a technician

If voltage is in spec but the over-voltage code persists, the heater electronics may be faulty — contact Truma service.

Applies to

Combi 4 · Combi 6 · Combi 4 E · Combi 6 E · Combi Eco Plus · Combi Comfort Plus

FAQ

What does Truma Furnace code "E43H" mean?

Over-voltage: the supply voltage to the heater is too high (Truma cites above roughly 16.4 V on CP plus / above ~15 V on older units). The electronics shut down to protect themselves.

How do I reset Truma Furnace E43H?

Bring the supply voltage back into the normal range; the fault generally clears on its own On CP plus, press and hold / double-click the displayed code and back out to acknowledge it if it persists

What is the most common cause of E43H on a Truma Furnace?

The most likely cause is battery charger / converter or solar charge controller pushing voltage too high.

Related · Truma furnace

E2H / E16H
VarioHeat ignition/flame fault: the furnace released gas and… E44H
Under-voltage: the supply voltage to the heater is too low (… E112H / E212H
Gas/flame fault group: the burner did not ignite or the flam… W18H
Warm-air outlet or circulated-air (return air) intake is blo… W25H–W29H
VarioHeat voltage and airflow warnings: W25H = overvoltage a…

Sources

Tech Tip: Truma Combi Error Codes — Truma Combi error code reference, E43H (Truma (official US site))
List of flash codes Combi 4 (E) / 6 (E) — Fault no. 43, over voltage higher than 15 V (Truma (OEM flash-code list via Dometic RV Centre))

Note: Voltage threshold differs slightly between CP plus (~16.4 V) and older flash-code list (~15 V); both confirm 'over-voltage'.

● Last verified 2026-06-29 · compiled from manufacturer documentation. Codes can vary by model year — always cross-check your unit’s manual.