Noritz NR98 & NR111 Code 12
Flame rod does not detect flame. The unit lit and lost the flame, or could not confirm it. Noritz lists accidental extinction of the flame, abnormal combustion, the gas solenoid valves, the flame rod, and the ground — especially on the circuit board. Worth knowing on this range: the table it belongs to also carries code 41 for the flow sensor, which the NCC199 and NRC111 table does not. A unit that lights and then loses flame at low draw is worth checking against that number too.
Also displayed as: F12
Call a proThe verdict
Call a licensed plumber
Confirm gas and check the vent terminal, then stop. The flame rod sits in the burner chamber and abnormal combustion is not something to diagnose by trial.
Typical cost: $0–$800
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 NR98 & NR111 — not averaged across the brand.
Source: Noritz Service Manual — NR50 / NR66 / NR71 / NR98 / NCC199 / NRC111 / NR111 / NC380 (Rev. July 2011) (p. 56), 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 gas is on at the heater and the meter.
- Check the vent terminal outside is clear.
- Note whether it fires and quits, or never fires at all.
- Call a licensed professional.
Code 12 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
One other Noritz NR98 & NR111 code points at flame detection 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: