HVACopediaNoritz · Tankless water heater · Pump/purge
Other recirculation modes
What happens, in order
- Manual Timer set the hours the pump runs with the app, copy one day to all weekdays
- On Demand (Title 24) pump runs only when a push button (WLB), motion sensor (WLB-MS) or rocker switch (IHK-RS) is activated
- Always Off pump never runs
- Always On pump runs continuously
- Crossover valve systems need a set temperature of at least 120 F
- Check the active mode with maintenance monitor MM86
Codes you may see during this
Applies to: Noritz NRCR92, NRCR111 (NRCR Pro)
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
- Freeze prevention heaters and pump · Freeze protection
Related
Take it to the job
Sequences of operation, error codes and tips work offline in the HVACopedia app.
Source: Noritz NRCR Pro Residential Condensing Recirculation training (NRCR Printable V3), recirculation modes section; Premix R2 training MM86 page. 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.