Navien E038 — Exhaust Temperature Sensor Fault

What Causes Navien E038?

Secondary exhaust sensor fault, distinct from E030. Indicates the rear exhaust thermistor is out of range. Common after repeated overheating events caused by scale.

How to Fix Navien E038

Address any underlying scale buildup first, then replace the sensor. Call us for a comprehensive Navien service that includes descaling and sensor replacement.

When to Call a Professional

Call Simple Water Heater & Filtration if:

• The error code returns after resetting
• You are not comfortable working with gas appliances
• The unit is making unusual sounds alongside the error
• This is the second time you have seen this code in the past year

We are factory-trained on Navien and provide repair service throughout Los Angeles, the San Fernando Valley, Westside LA, and Ventura County.