Noritz EZ Series & NCC199CDV Code 71
Gas valve drive circuit fault. The circuit driving the gas valve has faulted. Noritz checks for damage to the gas valve drive circuit on the circuit board, and then measures the resistance through both high limit switches — the primary heat exchanger one and the burner chamber one. If the display persists after a power cycle, Noritz says to contact the nearest agent.
Also displayed as: F71
Call a proThe verdict
Call a licensed plumber
Noritz pulling both high limit switches into the diagnosis is the detail worth knowing: this code can be the board, or it can be a safety circuit that is open somewhere. Either way it is the gas control side of the appliance and not a homeowner job.
Typical cost: $300–$1,200
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 EZ Series & NCC199CDV — not averaged across the brand.
Source: Noritz Service Manual — NRC663 FSV, EZ98DV, EZ111DV, NCC199CDV (Rev. Oct 2017) (p. 32), 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.
- Cycle the power once, which is Noritz's documented reset.
- If the code persists, leave the unit off and call a licensed professional or a Noritz agent.
Code 71 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: