HVACopediaICP · Heat pump · Heating
Heat pump: heating cycle with supplemental heat
What happens, in order
- On a call for heat the thermostat makes R-Y and R-G only (no R-O, so the reversing valve stays in heating position)
- R-Y energizes the contactor, starting outdoor fan and compressor; R-G starts the indoor blower
- If the room keeps falling, R-W2 through the second-stage thermostat energizes a sequencer for the first bank of supplemental electric heat and feeds the second sequencer if fitted
- Below the field-installed outdoor thermostat setting the second bank of supplemental heat comes on
- Thermostat satisfied contactor, blower relay and sequencer drop out and compressor, motors and heaters stop
Applies to: ICP N4H3 heat pump
Models
More ICP heat pump sequences
- Heat pump: cooling cycle · Cooling
- Heat pump: defrost board interval and defrost timers · Defrost
Related
Take it to the job
Sequences of operation, error codes and tips work offline in the HVACopedia app.
Source: ICP N4H3 heat pump installation instructions (428 01 5103), Defrost Control Board and Sequence of Operation. 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.