Noritz Tankless Water Heater: Draining to prevent freezing – Noritz EZ/NRCR
Draining to prevent freezing - Noritz EZ/NRCR on a Noritz tankless water heater: Drain the heater when it will be unpowered or unused in freezing conditions. The unit must stay plugged in for freeze protection.
Applies to: Noritz EZ111/EZ98/EZ71 and NRCR111/NRCR92
Common causes of draining to prevent freezing - noritz ez/nrcr
- Power loss in cold weather
- Vacant home
How to fix draining to prevent freezing - noritz ez/nrcr: step by step
- WARNING: Turn the heater off and let it cool first.
- Using the display: power button off > menu > Drain Water > Start (or app: User Setting > Drain Water on).
- Close the water supply valve and open all hot fixtures.
- EZ: open all drain plugs. NRCR: open drain plug A (hot side), drain plug with filter B (cold side), then C, D and E, or use the isolation valve ports.
- Manual draining without power: close gas, run hot water over 2 minutes per unit; code 11 or 41 may show and is not a fault.
- Refit all plugs; if unpowered, blow remaining water out with an air compressor.
- DANGER: when restarting, the condensate trap must refill - run the unit and confirm condensate drains within about 15 minutes.
If the unit shows an error code, look it up: Noritz Tankless Water Heater codes
Models
Noritz EZ
Noritz NRC/NRCP
N-0841MCN-0841MC-DVN-0842MCN-0842MC-DVNRC111-DVNRC111-SV
Noritz CDV
Noritz NRCR
Source: Noritz EZ/NRCR Owner's Guide (Rev. 10-25), Preventing damage from freezing, p.24-25. Written in our own words as a summary; always check the original manual.
General guidance for qualified technicians. The manufacturer's installation and service manual and local codes always take priority. Aurora Star Tech is not affiliated with, endorsed by or sponsored by any equipment manufacturer; brand and model names are used only to identify equipment and belong to their owners.