Navien · Water heater
E030 Abnormal exhaust temperature
What this code means
The exhaust (flue) temperature has exceeded the safe limit — commonly cited around 149°F (65°C) — and the exhaust high-limit switch shuts the unit down as a safety measure. Distinct fault from E010's air-pressure reading.
Most likely causes
- Blocked flue terminal, often from a bird nest or debris
- Fan issues restricting proper exhaust flow
- Clogged inlet water filter contributing to overheating
What to try first
Turn the unit off for 30 minutes, clean the inlet water filter, and visually check the exterior flue terminal for blockage before restarting.
Safety note: if this code returns after one clean reset, stop resetting it — repeated lockouts usually mean a real fault that needs a licensed technician. Never bypass a safety switch.
FAQ
What does Navien error code E030 mean?
Abnormal exhaust temperature. The exhaust (flue) temperature has exceeded the safe limit — commonly cited around 149°F (65°C) — and the exhaust high-limit switch shuts the unit down as a safety measure. Distinct fault from E010's air-pressure reading.
Can I fix Navien code E030 myself?
Usually not. Turn the unit off for 30 minutes, clean the inlet water filter, and visually check the exterior flue terminal for blockage before restarting. If the code returns after one reset, it needs a licensed technician.
What causes Navien code E030?
The most common causes are: blocked flue terminal, often from a bird nest or debris; fan issues restricting proper exhaust flow; clogged inlet water filter contributing to overheating.
Other Navien water heater codes
All Navien water heater error codes →
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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.