Noritz NRCP Eco TOUGH Code Er94
Exhaust overheating. The flue is too hot. Noritz's remedies on this generation are to turn the water heater off for at least thirty minutes and restart it, clean the cold water inlet filter, and flush the heat exchanger. The first-generation manual instead names LP gas supplied to a natural gas unit as a cause and states the shutdown threshold of 149 °F; neither appears here. Manual reset.
Also displayed as: 94, E94
Call a proThe verdict
Call a licensed plumber
Noritz's remedies here are all maintenance — the wait, the filter, the flush — which points at a scaled heat exchanger no longer moving heat into the water. Do them. But an exhaust running hot is still a combustion symptom, so if it returns after a genuine flush, stop resetting and get it looked at.
Typical cost: $0–$1,000
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 Eco TOUGH — not averaged across the brand.
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 exact series.
What you can safely check
Before anything else: if you smell gas, stop here, leave, and call your gas utility.
- Turn the water heater off for at least thirty minutes before restarting it.
- Clean the cold water inlet filter.
- Flush the heat exchanger.
- If Er94 returns after a proper flush, call a licensed professional rather than resetting again.
Frequently asked questions
The first-generation manual gives a temperature for this code. Does mine have one?
Not in this table. The NRCP111 and NRCP98 manual states that the heater shuts down when the flue temperature exceeds 149 °F (65 °C); the Eco TOUGH manual gives the remedies without the threshold. The mechanism is the same — a condensing appliance should not be sending that much heat up the vent — but we do not state a number this document does not.
Code Er94 on other Noritz series
The same code number can mean something different on another series — make sure you're reading the page for your exact unit: