Noritz tankless water heater code Er16
Overheating. Code Er16 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 Er16 means on each Noritz series
| Series | What it means | Verdict | Typical cost |
|---|---|---|---|
| NRCP | Overheating | DIY fix | $0–$400 |
| NRCP Eco TOUGH | Overheating | DIY fix | $0–$400 |
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 Er16 — 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 Er16 agree and where they part company.
NRCP — Overheating
The heat exchanger and hot water temperature sensors are reporting an overheat. Every remedy Noritz gives for this code is maintenance you can do: switch the main power off and on, clean the cold water inlet filter and the recirculation return filter, and flush the heat exchanger. That is a manufacturer telling you the usual cause is restricted flow or scale rather than a failed part.
NRCP Eco TOUGH — Overheating
The heat exchanger and hot water temperature sensors are reporting an overheat. Noritz's first remedy on this generation is distinctive: turn the water heater off for at least thirty minutes and then restart it. After that, clean the cold water inlet filter and the recirculation return filter, and flush the heat exchanger. Noritz marks it auto reset, so the unit will clear the code itself once conditions allow.
Does it matter which Noritz you have?
NRCP and NRCP Eco TOUGH all route code Er16 the same way: a descale, at $0–$400. That makes it one of the Noritz numbers you can act on before working out which unit you own.
Which Noritz do you have?
On the 2 series that report code Er16, 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 Er16
Code Er16 on these 2 Noritz series points at 3 guides, 3 parts and 3 symptoms, each named by the manufacturer's own procedure for this code.