Rinnai · Water heater
Code 10 Exhaust / venting obstruction
What this code means
The unit isn't detecting proper exhaust flow, which shuts it down as a carbon-monoxide safety precaution.
Most likely causes
- Blocked vent termination outside (leaves, snow, insects, nests)
- Disconnected or damaged vent piping
- Undersized or overly long vent run
What to try first
Inspect the exterior vent cap and clear any visible blockage; do not proceed if you smell gas or suspect a disconnected vent.
Safety first: stop using the appliance and shut off its gas or power until it has been inspected — this fault category is associated with fire or gas risk.
FAQ
What does Rinnai error code Code 10 mean?
Exhaust / venting obstruction. The unit isn't detecting proper exhaust flow, which shuts it down as a carbon-monoxide safety precaution.
Can I fix Rinnai code Code 10 myself?
No — stop using the appliance and shut off its gas or power until it has been inspected. This fault category is associated with fire or gas risk.
What causes Rinnai code Code 10?
The most common causes are: blocked vent termination outside (leaves, snow, insects, nests); disconnected or damaged vent piping; undersized or overly long vent run.
Other Rinnai water heater codes
All Rinnai water heater error codes →
Other water heater brands: Rheem · Ruud · Navien · Noritz · Takagi · A.O. Smith · Bradford White · State / American · Generic electric · Generic tankless
This information may contain errors or not apply to your exact model — always double-check it against your appliance's own manual before acting. If there's any chance of a gas, fire, electrical, carbon monoxide, or other safety hazard, stop and call a licensed professional or the appropriate agency (e.g. your gas utility) instead of relying on this page alone.