Noritz NR98 & NR111 Code 30
Air inlet thermistor fault. The sensor reading incoming air temperature is out of range. Noritz measures its resistance, checks for an open or short circuit, and checks its connection. Noritz references this sensor as component 29 in the p. 56 table's diagram, where the NCC199 and NRC111 table numbers the same sensor 19. If a technician is working from the wrong page the reference will not match what they find.
Also displayed as: F30
Part replacementThe verdict
Replace a part
Cheap sensor, quick job, but inside the cabinet of a gas appliance so it is a service call. Nothing about the fault is dangerous — the unit has lost one of its inputs.
Typical cost: $120–$400
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
- Book a service call. Noritz lists no homeowner check for this code.
Code 30 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 NR98 & NR111 codes point at a thermistor 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: