Noritz tankless water heater code Er45
Water leak detected. Code Er45 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 Er45 means on each Noritz series
| Series | What it means | Verdict | Typical cost |
|---|---|---|---|
| NRCP | Water leak detected | Call a pro | $200–$1,500 |
| NRCP Eco TOUGH | Water leak detected | Call a pro | $200–$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 Er45 — 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 Er45 agree and where they part company.
NRCP — Water leak detected
The unit has detected a water leak inside itself. Noritz's remedies are to check the leaking point if possible, and to contact technical support. There is no repair procedure in the table, because water inside a cabinet full of mains electronics and gas controls is not a fault to work around.
NRCP Eco TOUGH — Water leak detected
The unit has detected a water leak inside itself. Noritz's remedies are to close the water inlet valve before contacting technical support, and then to contact technical support. The order is deliberate — the valve first, the phone call second. Manual reset.
Does it matter which Noritz you have?
NRCP and NRCP Eco TOUGH all route code Er45 the same way: a professional, at $200–$1,500. That makes it one of the Noritz numbers you can act on before working out which unit you own.
What to check first, whatever your series
These checks are on the manufacturer's list for every Noritz series that reports code Er45, so they are safe to work through before you have identified your exact unit. They also cost nothing.
- Call a licensed professional or Noritz technical support.
That is 1 of the 4 checks documented for code Er45. The rest differ by generation, so if none of those explains it, go to your own series above.
Which Noritz do you have?
On the 2 series that report code Er45, 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 Er45
Code Er45 on these 2 Noritz series points at 2 parts and 2 symptoms, each named by the manufacturer's own procedure for this code.