Noritz NRCP Code Er39
Flame detected after the gas valve closed. The unit shut the gas valve and still saw a flame signal. Noritz's remedies are to make sure the front cover is closed securely and to check the flame sensor voltage, which should read 5 VDC when the flame is off. The front cover appearing in a flame-detection remedy is not an accident — this is a sealed-combustion appliance and the cover is part of the air circuit.
Also displayed as: 39, E39
Call a proThe verdict
Call a licensed plumber
One check is genuinely yours and takes ten seconds: is the front cover properly closed and latched. If it is, the remaining item is a voltage measurement on the flame sensor of a gas appliance, which is not.
Typical cost: $0–$700
US estimate for parts and labor. Prices vary by region and by who does the work — see how we estimate costs.
What the manual says
The meaning above is transcribed from the manufacturer's diagnostic documentation for the NRCP — not averaged across the brand.
Source: Noritz Service Manual — NRCP111-DV / NRCP98-DV (Rev. 09/19) (p. 62), read Sep 2026 — the manufacturer's own documentation for this exact series.
What you can safely check
Before anything else: if you smell gas, stop here, leave, and call your gas utility.
- Check the front cover is fully seated and latched — Noritz lists it first for this code.
- If the cover is secure and Er39 stays, call a licensed professional.
Code Er39 on other Noritz series
The same code number can mean something different on another series — make sure you're reading the page for your exact unit:
Don't confuse this with
3 other Noritz NRCP codes point at a valve too. They are different components in different places, and ordering a part against the wrong one is the most common way this fault gets expensive: