HVACopediaNoritz · Tankless water heater · Freeze protection
Freeze prevention heaters and pump
What happens, in order
- Freeze prevention heaters (and the recirc pump on NRCR) run on their own to keep the unit from freezing
- Heaters only protect the unit, not the outside plumbing, so use heat tape or insulation
- In extreme cold follow the manual's extra cold-weather measures
- If the unit will be off or power is lost for long, drain it using the drain plugs and isolation valves
- Freeze prevention operation can show in the display status notices
Applies to: Noritz EZ and NRCR tankless
Models
More Noritz tankless water heater sequences
- On-demand heating cycle · Domestic hot water
- Water route: main and bypass servo by set temperature · Domestic hot water
- Auto Learning recirculation · Pump/purge
- Other recirculation modes · Pump/purge
Related
Take it to the job
Sequences of operation, error codes and tips work offline in the HVACopedia app.
Source: Noritz EZ (EZ111-EZ98-EZ71) + NRCR owner/operation manual Rev. 10-25, Preventing Damage from Freezing. Written in our own words; timings can differ by model and software version, so check the manual for your exact unit.
For licensed technicians. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Shut off power and gas before servicing, never bypass a safety control, and follow the manufacturer’s manual for the exact model; it and local codes always take priority. HVACopedia is not affiliated with any manufacturer; brand and model names only identify the equipment.