Noritz EZ Series & NCC199CDV Code 72
Flame rod circuit fault. The unit believes it can see a flame when there should not be one. Noritz measures the current from the flame rod with no flame present and checks for a ground fault. It is the reverse of code 12: not failing to see a real flame, but seeing one that is not there. Unlike every other Noritz range on this site, a false flame reading here shares an appliance with a wired carbon monoxide alarm at code 13. That does not change the diagnosis, but it does change the urgency of getting it looked at rather than resetting past it.
Also displayed as: F72
Call a proThe verdict
Call a licensed plumber
A false flame signal matters because the logic that decides whether it is safe to open the gas valve depends on it. If it does not clear on a power cycle, leave the unit off.
Typical cost: $150–$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 EZ Series & NCC199CDV — not averaged across the brand.
Source: Noritz Service Manual — NRC663 FSV, EZ98DV, EZ111DV, NCC199CDV (Rev. Oct 2017) (p. 32), 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.
- Cycle the power once.
- If 72 returns, switch the unit off and leave it off.
- Call a licensed professional — a ground fault is one of the two named causes and it needs measuring.
Code 72 on other Noritz series
Other Noritz series report code 72 under the same fault name, but each manual is transcribed separately and they do not read alike:
Don't confuse this with
One other Noritz EZ Series & NCC199CDV code points at flame detection too. They are the same symptom reported from a different place in the unit, so which one the display shows is what tells you where to look: