Navien · Water heater
E002 Low water pressure
What this code means
Insufficient water flow through the heater, which can trigger a safety shutdown until pressure/flow is restored.
Most likely causes
- Closed or partially closed water valve
- Clogged inlet filter
- Insufficient household water pressure
What to try first
Ensure all valves are fully open and clean the inlet water filter; the unit will often reset automatically once pressure returns to normal.
Good news: this one is often fixable without a service call. If it persists after the steps above, have it looked at.
FAQ
What does Navien error code E002 mean?
Low water pressure. Insufficient water flow through the heater, which can trigger a safety shutdown until pressure/flow is restored.
Can I fix Navien code E002 myself?
Often, yes. Ensure all valves are fully open and clean the inlet water filter; the unit will often reset automatically once pressure returns to normal.
What causes Navien code E002?
The most common causes are: closed or partially closed water valve; clogged inlet filter; insufficient household water pressure.
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.