Noritz tankless water heater code Er40
Gas leakage. Code Er40 means the same thing on all 2 Noritz series documented here — but the fix, and what it costs, is still worth reading for your exact unit.
What code Er40 means on each Noritz series
| Series | What it means | Verdict | Typical cost |
|---|---|---|---|
| NRCP | Gas leakage | Emergency — stop | $0–$1,500 |
| NRCP Eco TOUGH | Gas leakage | Emergency — stop | $0–$1,500 |
Each row opens the full page for that generation. We hold manuals for NRCP and NRCP Eco TOUGH, and each one gets its own reading of code Er40 — what Noritz documents, what you can safely check yourself, and what the repair should cost.
What each manual actually says
The table above compares 2 series in four columns, which is enough to route you and not enough to explain anything. This is the Noritz wording behind each row, one entry per manual, so you can see where the 2 readings of code Er40 agree and where they part company.
NRCP — Gas leakage
The appliance has detected gas leakage. Noritz's remedy column is two lines and neither is a repair: close the gas supply valve, and contact technical support. There is no diagnostic step, no resistance to measure and no part named, because at this point the correct action is not diagnosis.
NRCP Eco TOUGH — Gas leakage
The appliance has detected gas leakage. Noritz's remedy column is two lines and neither is a repair: turn off the gas, and contact technical support. There is no diagnostic step and no part named. Manual reset — the unit will not decide on its own that the danger has passed.
Does it matter which Noritz you have?
NRCP and NRCP Eco TOUGH all route code Er40 the same way: a professional, at $0–$1,500. That makes it one of the Noritz numbers you can act on before working out which unit you own.
At least one Noritz series treats this code as an emergency. Read your own series page before doing anything else with the appliance.
Which Noritz do you have?
On the 2 series that report code Er40, the model number on the rating label starts NRCP — match yours against the 4 listed below. You can also use the full model-number decoder.
Where this comes from
Source: Noritz Service Manual — NRCP111-DV / NRCP98-DV (Rev. 09/19) (p. 62), read Sep 2026 — the manufacturer's own documentation for this Noritz range.
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 Noritz range.
Parts, guides and symptoms behind code Er40
Code Er40 on these 2 Noritz series points at 2 parts and 1 symptom, each named by the manufacturer's own procedure for this code.