Noritz NRCP Code Er45
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.
Also displayed as: 45, E45
Call a proThe verdict
Call a licensed plumber
Shut the water off to the heater and leave it off. Water sitting in an appliance that runs mains voltage and gas valves is a hazard beyond the leak itself, and the damage compounds every hour it is left.
Typical cost: $200–$1,500
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 — not averaged across the brand.
Source: Noritz Service Manual — NRCP111-DV / NRCP98-DV (Rev. 09/19) (p. 62), read Sep 2026 — the manufacturer's own documentation for this exact series.
What you can safely check
- Close the cold water isolation valve at the heater.
- Switch the unit off at the breaker — not just at the controller.
- Look for where water is escaping if it is visible from outside the cabinet, but do not open it.
- Call a licensed professional or Noritz technical support.
Frequently asked questions
It is only a drip. Do I really need to shut it down?
Yes. The sensor that triggered Er45 is in the bottom of a cabinet containing the circuit board, the igniter circuit and the gas valve. A drip that has reached the tray has already been running somewhere above it, and a cracked heat exchanger is one of the ways this code appears.
Code Er45 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: