Noritz EZ Series & NCC199CDV Code 36
Heat exchanger inlet thermistor fault. The sensor on the inlet of the primary heat exchanger is out of range. Noritz measures its resistance, checks for an open or short circuit, and checks the connection. This code does not exist on the NRC series at all — that generation has one heat exchanger thermistor where this one has two.
Also displayed as: F36
Part replacementThe verdict
Replace a part
Cheap sensor inside the cabinet. It is the partner of code 33 and the same visit, but a different part number, so it is worth being precise when you book.
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 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
- Tell the technician it is code 36 — the heat exchanger inlet thermistor, not the outlet one.
- Book a service call.
Frequently asked questions
My Noritz shows 36 but every code list online stops at 35. Why?
Because most lists are written for a different Noritz. The NRC661, NRC711 and NRC663 tables have no code 36 — they only carry one heat exchanger thermistor. The EZ98DV, EZ111DV and NCC199CDV have an inlet and an outlet sensor, so they need an extra number for it.
Don't confuse this with
5 other Noritz EZ Series & NCC199CDV 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: