Winnebago’s camper vans lean heavily on Truma for heat and hot water — but “Truma” is not one system, and half of all troubleshooting frustration starts with following instructions for a unit your van doesn’t have. Here’s the correct map, the error codes that matter, and the reset logic that actually works.

Which Van Has Which Truma

  • Solis 59P / 59PX: Truma Combi Eco — gas (propane) furnace + water heater in one unit.
  • Boldt (and Travato/Era): Truma Combi Eco Plus — same concept plus electric heating elements, so it can run on shore power, gas, or both.
  • Solis Pocket 36A: Truma VarioHeat furnace (no combined water heater).
  • EKKO: no Combi at all — it pairs a VarioHeat furnace with an AquaGo Comfort Plus tankless water heater. If you’ve been searching “EKKO Combi problems,” that’s why nothing matched.

Everything below applies to the Combi family; VarioHeat and AquaGo share the brand’s diagnostics philosophy but have their own code tables.

The Two Error Codes Everyone Meets

E212H — the combustion air path is blocked, the gas valve is closed, or the unit hit overheating protection. First checks: is the propane actually on (tank valve and any inline shutoffs), and is the exterior intake/exhaust cowl clear? Wasps, mud daubers, and winter covers left in place cause a remarkable share of these.

E517H — gas-supply failure lockout: the unit tried to ignite repeatedly and gave up. Classic causes are an empty or nearly empty propane tank, a regulator problem, or air in the line after a tank swap. Important quirk: several codes in this family (507/516/517) impose a 15-minute blocking period before the unit will even attempt another start — repeatedly stabbing the power button during that window does nothing except convince you it’s broken.

The Reset That Actually Works

There is no magic hidden reset: the procedure is fix the root cause first (gas on, cowl clear, battery healthy), then switch the unit fully off at the CP Plus control panel, wait out any blocking period, and restart. If a code returns immediately after a proper reset with the cause addressed, that’s your signal to stop cycling and call Truma — persistent lockouts are designed to require service attention, not more button presses.

Voltage: the Silent Truma Killer

The Combi is voltage-sensitive by design: the control panel warns below about 10.4V and the unit shuts gas operation down below roughly 10.0V. A tired house battery on a cold night — exactly when you want heat most — will produce mysterious shutdowns that look like furnace faults. Before blaming the Truma, check battery voltage under load (furnace blower running). Half of all “my Combi died at 3 AM” stories are battery stories.

Cold Weather Notes

The Combi has built-in frost protection for its own water content — but that protection drains your battery if you store the van cold with the system wet. Winterize (drain) for storage rather than letting frost protection babysit an unattended van. And keep the exterior cowl clear of snow before firing the furnace — a blocked cowl is an instant E212H.

When You Need a Human

Truma North America runs from Elkhart, Indiana, with company service centers plus a network of 300+ certified Service Partners across the US and Canada — and a genuinely useful phone line (1-855-558-7862). Because the certified network is thinner than, say, Dometic’s, calling ahead beats driving to a random RV shop that has never opened a Combi.

Related Guides

Diesel-heat vans instead? See Timberline troubleshooting and Winnebago Timberline error codes. Year pages: 2023 Solis heater not working. Or describe your exact symptoms to the free AI at SprinterRVDesk.com.