Noritz tankless water heater code Er70
Your series decides which reading applies. Across the 2 Noritz series documented here, code Er70 is listed as circuit board fault (1 series) and circuit board processor error (1 series). Find your series in the table below, where those readings route to a replacement part.
What code Er70 means on each Noritz series
| Series | What it means | Verdict | Typical cost |
|---|---|---|---|
| NRCP | Circuit board fault | Part replacement | $0–$900 |
| NRCP Eco TOUGH | Circuit board processor error | Part replacement | $0–$900 |
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 Er70 — 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 Er70 agree and where they part company.
NRCP — Circuit board fault
The circuit board has reported a fault in itself. Noritz's remedy is to try the main power switch off and on, and states the conclusion if that fails: still the same error means circuit board failure.
NRCP Eco TOUGH — Circuit board processor error
Noritz calls this a MICOM error on the PCB — the microcontroller on the circuit board reporting a fault in itself. The remedy is to try to reset first, and if the same error code returns, contact technical support. Auto reset.
Does it matter which Noritz you have?
NRCP and NRCP Eco TOUGH all route code Er70 the same way: a replacement part, at $0–$900. 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 Er70, so they are safe to work through before you have identified your exact unit. They also cost nothing.
- Switch off at the breaker, wait a full minute, switch back on.
That is 1 of the 3 checks documented for code Er70. 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 Er70, 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 Er70
Code Er70 on these 2 Noritz series points at 1 guide, 1 part and 2 symptoms, each named by the manufacturer's own procedure for this code.