HVACopediaRinnai · Tankless water heater · Pump/purge
Circ-Logic external recirculation pump
What happens, in order
- Water heater PCB controls the on and off cycles of an external recirculation pump through its parameter settings
- Economy mode (05A) cycles the pump less often to save energy
- Comfort mode (05b) cycles the pump more often to keep the loop hotter
- Do not install a thermal bypass (crossover) valve on a dedicated return system
Codes you may see during this
Applies to: Rinnai tankless with external pump harness
Models
More Rinnai tankless water heater sequences
- Smart-Circ recirculation · Pump/purge
- Built-in freeze protection and power loss · Freeze protection
Related
Rinnai error codes · Rinnai tips · Rinnai parts · All Rinnai sequences
Take it to the job
Sequences of operation, error codes and tips work offline in the HVACopedia app.
Source: Rinnai SENSEI RX Installation and Operation Manual (100000839), recirculation and parameter sections; also RSC and N-Series manuals, External Pump with Circ-Logic. 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.