e047
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Navien · Tankless Water Heaters
Exhaust thermostat abnormal operation.
Quick Answer
Error code E047 on your Navien Tankless Water Heaters means: Exhaust thermostat abnormal operation.. This is usually fixable — see the step-by-step guide below.
Affected Models
Likely Causes
How to Fix It
1
Turn unit off and inspect vent termination for blockage.
2
Allow cooldown and restart once.
3
If code returns, schedule service.
4
Technician should measure sensor behavior and wiring continuity.
5
Replace thermostat/sensor as needed.
Pro Tip
This issue typically requires professional diagnosis. Attempting this fix without proper training could cause further problems.
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