Noritz NCC199 & NRC111 Code 72
Flame rod circuit fault. The unit is detecting 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.
Also displayed as: F72
Call a proThe verdict
Call a licensed plumber
A false flame signal is a safety fault, because the logic that decides whether it is safe to open the gas valves depends on that reading being honest.
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 NCC199 & NRC111 — not averaged across the brand.
Source: Noritz Service Manual — NR50 / NR66 / NR71 / NR98 / NCC199 / NRC111 / NR111 / NC380 (Rev. July 2011) (p. 55), 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.
- Cut the power for a minute and restore it.
- 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 NCC199 & NRC111 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: