Noritz NRCP Code Er46
Low recirculation flow. The recirculation loop is not moving enough water. Noritz's remedies are the return and cold water filters, verifying the recirculation loop length is within specification, checking the recirculation flow rate in User Mode, and checking the recirculation setting — Noritz names the wrong combinations explicitly: External or On-Demand set without a dedicated return line, and External or On-Demand set with a crossover valve. This code does not exist on the Eco TOUGH generation.
Also displayed as: 46, E46
DIY fixThe verdict
No parts needed — reset or re-check a setting
Two filters and a setting, and all three are within reach. The setting is the one worth checking first if anything about the plumbing changed recently — Noritz names the exact wrong combinations, which is unusually specific for a service manual.
Typical cost: $0–$600
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 — not averaged across the brand.
Source: Noritz Service Manual — NRCP111-DV / NRCP98-DV (Rev. 09/19) (p. 62), read Sep 2026 — the manufacturer's own documentation for this exact series.
What you can safely check
- Clean the recirculation return line filter and the cold water inlet filter.
- Check the recirculation flow rate in User Mode on the controller.
- Check the recirculation setting matches the plumbing: Noritz flags External or On-Demand set without a dedicated return line, and the same settings used with a crossover valve, as wrong combinations.
- If the loop was recently extended, have its length checked against Noritz's specification.
- If none of that clears it, book a service call for the pump.
Frequently asked questions
My Eco TOUGH does not have an Er46. Where did it go?
Noritz dropped the number on the second generation and folded low recirculation flow into Er44, which it renamed "recirculation abnormality". If you have an NRCP1112-DV or NRCP982-DV, the equivalent guidance is on that series' Er44 page.