Noritz NR98 & NR111 Code 41
Flow sensor fault. The flow sensor is not reporting properly. Noritz's remedy is one line — check the flow sensor for debris and/or damage — and debris is named first for a reason: the sensor has a small impeller in the water path, and grit from a water main repair or a well will stop it turning long before it breaks. This code is not on the NCC199 and NRC111 table.
Also displayed as: F41
Part replacementThe verdict
Replace a part
The named cause is debris rather than failure, which makes this one of the cheaper outcomes in the table — but the sensor is in the water circuit inside the cabinet, so it needs the supply isolated and the unit drained. Ask about the inlet filter at the same time, since that is what should have caught the debris.
Typical cost: $150–$500
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 NR98 & NR111 — not averaged across the brand.
Source: Noritz Service Manual — NR50 / NR66 / NR71 / NR98 / NCC199 / NRC111 / NR111 / NC380 (Rev. July 2011) (p. 56), read Sep 2026 — the manufacturer's own documentation for this exact series.
What you can safely check
- Note whether anything happened to the water supply recently — a main repair, well work, or the system being drained and refilled.
- Ask the technician to check and clean the inlet water filter on the same visit.
- Book a service call.