Navien water heater shows E038; unit may lock out and not restart.
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Possible Causes
How to Fix / Troubleshooting
Safety: Turn OFF power before working on the condensate system. Condensate is mildly acidic; wear gloves and eye protection.
Steps:
- 1. Inspect condensate trap: Locate the condensate trap at the bottom of the unit. Check for sludge, debris, or scale buildup. Remove and flush the trap with clean water if accessible.
- 2. Check drain line: Follow the condensate hose to its termination. Ensure it is not kinked, frozen, or routed uphill. Clear any visible blockages.
- 3. Verify air gap: Ensure the condensate line terminates with an air gap into a drain and is not submerged, which can cause backpressure.
- 4. Refill trap: After cleaning, refill the trap with clean water to restore the seal before restarting the unit.
If E038 continues, the internal pressure sensing or trap assembly may be faulty and should be inspected by a technician.
Repair Difficulty
Required Part
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