Noritz NRCP Eco TOUGH Code Er33
Heat exchanger thermistor open or short. The heat exchanger sensor is open or short circuit, with the same shared remedies and the same auto reset. The reset column is the difference from the first generation. Noritz marks this one auto reset here; the NRCP111 and NRCP98 table has no reset column at all, so on that generation you are not told whether to expect the code to clear itself.
Also displayed as: 33, E33
Part replacementThe verdict
Replace a part
Cheap sensor, service call to reach it. Ask about scale while someone has the unit open — a sensor on a furred heat exchanger reads late even when it is healthy.
Typical cost: $120–$450
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 NRCP Eco TOUGH — not averaged across the brand.
Source: Noritz Service Manual — NRCP1112-DV / NRCP982-DV Eco TOUGH (Rev. 05/19) (p. 58), read Sep 2026 — the manufacturer's own documentation for this exact series.
What you can safely check
- Ask the technician to check the heat exchanger for scale while it is open.
- Book a service call.
Code Er33 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 NRCP Eco TOUGH 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: