Navien E016 — Overheating — High Exhaust Temperature

What Causes Navien E016?

The exhaust temperature exceeded safe limits. In Los Angeles, this is almost always caused by scale buildup in the heat exchanger restricting flow and causing thermal runaway.

How to Fix Navien E016

Annual descaling prevents this entirely. If you see E016, the unit needs descaling immediately — continued operation risks permanent heat exchanger damage.

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.