If your Truma Combi 6E combi boiler is struggling to light, blowing cold air, or throwing error codes, the first question is usually: should I repair the existing unit or replace the whole heater? This guide walks through the practical decision factors so you spend money in the right place — and tells you exactly what to check before you buy anything.
When to repair first
Repair is usually the right call when the problem is a single, replaceable wear part and the rest of the heater is still sound. Common candidates:
- Glow plug (igniter) — hard starting, repeated failed-ignition codes.
- Circulation / combustion blower — weak airflow, rattling, or a specific fault code tied to the fan.
- Fuel or water pump — no fuel delivery, or poor hot-water circulation.
- Flame / temperature sensor — flame-out codes or erratic shutdown.
Before ordering any part, note the OE number stamped on the old component and check the voltage (12 V vs 24 V) on the heater’s nameplate. Wear parts are brand- and model-specific — do not cross-match Truma, Webasto and Eberspächer parts. For general fault-code guidance on parking heaters, see our Webasto fault code guide and Airtronic fault code guide.
When to replace the whole unit
Replacing the complete combi heater tends to make sense when:
- The heater has failed repeatedly in the same season, and the cost of diagnosing each time keeps climbing.
- There is a major internal failure — heat exchanger, combustion-chamber corrosion, or a burnt-out burner assembly — where the labour and parts approach the price of a new unit.
- Downtime matters: you are on the road or the rig is off-sale while the heater sits in the workshop.
- The original cutout still matches, so you can do a clean drop-in swap without re-cutting the wall.
Our 6 kW LPG combi air & water heater is built as a direct drop-in replacement for the Truma Combi 6E cutout (460 × 450 × 270 mm), heating both cabin air and domestic hot water from one propane burn and one 12 V control.
Repair vs replace — side by side
| Factor | Repair the existing unit | Replace with a compatible combi |
|---|---|---|
| When it fits | One known, replaceable wear part; rest of unit sound | Repeat failures, major internal damage, or long workshop downtime |
| Cost picture | Lower upfront; but labour adds up on repeat visits | One purchase; includes both air + water in a single appliance |
| Downtime | Depends on part availability and your own labour | Clean drop-in swap if cutout matches |
| Typical failure handled | Ignition, airflow, pump, sensor | Heat exchanger / combustion-chamber failure, recurring faults |
Every install is different, so use this as a starting point rather than a rule.
Checklist before you buy or swap
- Voltage — confirm the heater is 12 V DC before ordering.
- Gas supply — propane line, regulator and any shut-off valve must match the replacement spec.
- Cutout size — our unit drops into the Truma Combi 6E footprint (460 × 450 × 270 mm); measure your opening.
- Water connections — check inlet/outlet routing and hose diameter for your fresh-water loop.
- Exhaust — sealed combustion with a balanced flue; confirm vent routing and clearances.
- Controls — the unit runs on a single 12 V control; confirm it integrates with your existing wiring.
FAQ
Can I drop-in replace a Truma Combi 6E?
Yes, if the cutout matches. Our 6 kW LPG combi heater is designed as a direct drop-in replacement for the Truma Combi 6E opening (460 × 450 × 270 mm), combining space heating and domestic hot water in one unit. Always verify your voltage and venting before swapping.
Should I repair first or replace?
Repair first when the fault is one known, replaceable wear part and the rest of the heater is sound. Replace when you face repeat failures, major internal damage, or long downtime that makes continued repair uneconomical.
Is it compatible with Canadian RV installs?
The unit is a 12 V LPG combi heater designed for motorhomes, campervans and travel trailers, and we ship across Canada with duties and taxes included in the price. Confirm your gas configuration and vent routing with a qualified installer before final fit.
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