Rinnai RH180 Hybrid Code FE
Flammable vapours detected. The RH180 has detected flammable vapours in the air around it and shut itself down. This is not a fault in the appliance — it is the appliance doing its job, and the manual's entire remedy column is an evacuation instruction rather than a repair procedure. Common sources are gasoline, solvents, paint thinners or adhesives stored or used near the heater. Rinnai's instruction is explicit: leave, leave the exit open behind you to ventilate, touch no electrical device, and call emergency services from a neighbour's phone.
Emergency — stopThe verdict
Call a licensed plumber
There is nothing to diagnose and nothing to price. Leave the building and call emergency services from outside it. The cost range below is for the service call afterwards, if the code persists once the area has been declared safe.
Typical cost: $0–$600
US estimate for parts and labor. Prices vary by region and by who does the work — see how we estimate costs.
What the manual says
The meaning above is transcribed from the manufacturer's diagnostic documentation for the RH180 Hybrid — not averaged across the brand.
Source: Rinnai RH180 Operation and Installation Manual (100000319) (p. 35), read Sep 2026 — the manufacturer's own documentation for this exact series.
Frequently asked questions
Can I reset FE myself once the smell has gone?
Only after safety personnel have identified the area as safe and the vapours have been removed. That is Rinnai's own condition. The reset itself is unplugging the unit and plugging it back in — but the condition comes first, and "I think it smells fine now" is not the condition.
What sets FE off if there is no gas leak?
Stored or spilled flammable liquids near the heater — gasoline for a mower, paint thinner, solvent-based adhesives. A water heater in a garage is the classic case. The sensor is doing what it was fitted to do.