Noritz NR98 & NR111 Code 70
Circuit board fault. The circuit board has reported a fault in itself. Noritz's entire diagnosis column is two words: circuit board failure. A board on this range has to be set for a model list spanning residential NR98 units and commercial ASME units, so a replacement is not a like-for-like swap — expect code 73, the setting fault, to follow a board change until the switches are configured.
Also displayed as: F70
Part replacementThe verdict
Replace a part
Cut the power for a minute and restore it. A board that faults once on a supply glitch may not fault again; if it comes back, it is the most expensive single part in the appliance.
Typical cost: $0–$900
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
- Switch off at the breaker, wait a full minute, switch back on.
- Run a hot tap and see whether the code returns.
- If it returns, book a service call — Noritz gives no other cause.
Code 70 on other Noritz series
Other Noritz series report code 70 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 NR98 & NR111 code points at the circuit board 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: