Noritz NRC Series Code 11
Ignition failure. The burner never lit. Noritz calls this initial flame fault detection: the unit went through its ignition sequence, looked for a flame at the end of it, and did not find one. The checklist is gas and spark — gas supply piping and pressure, igniter spark, the gas solenoid valves, the flame rod, and the ground connection at the circuit board, which Noritz singles out for special attention because flame detection depends on a good earth.
Call a proThe verdict
Call a licensed plumber
One check is yours and it is free: is the gas actually turned on. After that the list is manifold pressure, solenoid valves and the igniter, all of which need a technician with a manometer. Do not sit there resetting it — each attempt puts unburned gas into the combustion chamber.
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 NRC Series — not averaged across the brand.
Source: Noritz Service Manual — NR501-OD, NR662-OD, NRC661, NRC711 (Rev. Dec 2013) (p. 28), 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 the gas is on at the heater's own valve and at the meter, and on propane that the tank is not empty.
- Try another gas appliance in the house — if nothing gas-fired works, the supply is the problem, not the heater.
- If any gas work was done in the house recently, say so when you book — air trapped in the supply produces exactly this.
- Call a licensed professional rather than repeating the reset.
Frequently asked questions
The window inside shows 11 and so does my controller. Is that normal?
Yes. Code 11 is one of the few on this unit where the display window and the remote controller show the same number. Most faults show three digits in the window and two on the controller.
Why does Noritz make a point of the ground connection?
Flame detection works by passing a tiny current through the flame to earth. A poor ground at the circuit board makes the unit unable to see a flame that is actually burning, so it shuts down and reports ignition failure. It is a common cause and a cheap fix when it is the answer.
Code 11 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: