Noritz Error 90 — Combustion Abnormality

What Causes Noritz Error 90?

The unit detected abnormal combustion — the flame was present but combustion characteristics were outside normal parameters. Can be caused by venting issues, gas pressure problems, or a dirty burner.

How to Fix Noritz Error 90

Error 90 requires professional diagnosis to identify whether the issue is venting, gas supply, or the burner assembly. Call us for prompt Noritz service.

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 Noritz and provide repair service throughout Los Angeles, the San Fernando Valley, Westside LA, and Ventura County.