Safety first: Turn the AquaGo off for propane odor, soot, exhaust damage, water leaking from the appliance, freeze damage or a fault that returns immediately. Burner, gas-valve and combustion work require Truma-qualified service.

Truma AquaGo faults appear differently depending on the control panel. A CP plus digital panel can display an alphanumeric code. With the analog dial, a fast yellow blink signals a fault and the red LED near the exterior rocker switch flashes the detailed pattern.

Count the entire sequence before resetting anything. In Truma's notation, S means a short flash and L means a long flash. A phone video makes the pattern much easier to replay accurately.

How to read an AquaGo flash code

  1. Leave the appliance in the faulted state long enough to preserve the evidence.
  2. Open the exterior access door without touching hot or moving components.
  3. Locate the red status LED below the rocker switch.
  4. Record several complete groups of short and long flashes.
  5. Match the pattern to the manual for the exact AquaGo and control panel.

Do not count the fast yellow wall-control warning as the detailed code. The red exterior LED provides the short/long sequence on analog-controlled installations.

E1 or S-S-S-S-S-S-S-L: no flame detected

Truma describes E1 as a failure to establish flame after the AquaGo makes its ignition attempts. Start outside the heater: confirm the propane cylinder contains fuel and the service valve is open. If a cylinder was just changed, other propane appliances may need normal air-purge time.

Stop if you smell propane, hear delayed ignition, see soot or find exhaust damage. Repeated resets will not repair a regulator, gas valve, igniter, burner or flame-sensing problem.

W27 or S-S-S-L-L-S-L-L: circulation pump running dry

W27 means the circulation pump is not producing the expected water flow. Air trapped in the hot-water plumbing is a common cause after de-winterizing or plumbing work. Truma advises opening the RV's hot faucets one at a time and allowing sputtering and trapped air to clear.

Also confirm the RV has water pressure, the AquaGo is not bypassed and the filter cartridge and drain lever are correctly installed. Do not run the appliance with an empty mixing vessel.

W29 or S-S-S-L-L-L-S-L: heat demand is too high

This warning can appear when several hot-water outlets are open and the burner is already at full output but cannot maintain the target temperature. Close extra hot faucets and test one outlet at a time. Very cold inlet water and unusually high flow increase the demand.

W29 does not automatically mean the burner is weak. First reduce simultaneous use and verify whether the warning clears under a normal single-fixture load.

W30 or S-S-S-L-L-L-L-S: freezing risk

Truma associates W30 with internal temperature below about 27°F (3°C). Treat it as a freeze-damage warning, not a nuisance code. Follow the AquaGo manual for draining, approved antifreeze protection and cold-weather operation.

If the appliance may already be frozen, do not fire the burner or force water through it. Allow safe thawing and inspect for leakage before returning it to service.

W31 or S-S-S-L-L-L-L-L: decalcification finished

W31 reports that the decalcification cycle has completed; it is not a failed component. Finish the shutdown and mode-return steps in the Truma instructions. If the AquaGo was accidentally placed in Clean mode, use the dedicated clean-mode recovery procedure rather than repeatedly cycling power.

Reset only after addressing the code

A reset is useful after the cause has been corrected. Before resetting, save the code, note whether the fault appeared at startup or during a long draw, and record outdoor temperature, propane status and water-flow behavior. Those details matter if the fault returns.

Codes outside this common group should be matched to the current AquaGo manual. Do not substitute a code definition from a different Truma product.

Repair difficulty and likely outcome

  • Reading a code and checking supplies: beginner-level.
  • Purging plumbing air or reducing demand: beginner-level when no leak or freeze damage is present.
  • Combustion, pump, sensor or internal wiring faults: Truma-qualified service.
  • Best evidence: the complete code or short/long flash pattern before power is cycled.

Related RV Solver pages

Frequently asked questions

Where is the Truma AquaGo fault LED?

On analog-control installations, the detailed red fault LED is behind the outside AquaGo access door near the appliance rocker switch.

What does Truma AquaGo E1 mean?

E1 means the AquaGo did not establish a flame during its ignition attempts. Check propane supply first and stop for odor, soot or delayed ignition.

Is Truma AquaGo W31 a failure?

No. W31 indicates the decalcification cycle has finished. Follow Truma's mode-return procedure to clear it.

Still narrowing it down?

The guided troubleshooter walks through the symptom in a safe order and points you toward the right RV system.

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Sources and review notes

Reviewed against manufacturer material on July 12, 2026. Always match instructions and replacement parts to the exact model, serial range and manual supplied with the RV.