Noritz NR50, NR66 & NR71 Code 71
Gas solenoid valve drive circuit fault. The circuit driving the gas solenoid valves has faulted. Noritz's check is damage to the gas solenoid valve drive circuit on the circuit board. Five flashes on an NR71 or N-0631S with no remote controller.
Also displayed as: 5 flashes
Call a proThe verdict
Call a licensed plumber
A gas control fault pointing at the board. Not one to keep resetting to get through the week, and there is nothing on Noritz's list for a homeowner to check.
Typical cost: $300–$1,000
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 NR50, NR66 & NR71 — not averaged across the brand.
Source: Noritz Service Manual — NR50 / NR66 / NR71 / NR98 / NCC199 / NRC111 / NR111 / NC380 (Rev. July 2011) (p. 54), 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.
- Leave the unit switched off.
- Call a licensed professional.
Code 71 on other Noritz series
Noritz keeps the same fault name for code 71 on some series and not others. Check the one that matches your rating label: