HVACopediaGoodman · Furnace · Heating
Dual fuel heat pump to gas furnace transition
What happens, in order
- Heat pump runs first on a W call when no balance point lockout is active.
- If the call is still present after the target runtime, the heat pump runs an extra stage up percentage, then the system switches to gas heat.
- Each transition is recorded as a strike against the heat pump.
- After the over target threshold strike count is reached, the heat pump is locked out and the furnace becomes primary heat.
- While locked out, the furnace runs low stage gas heat; a satisfied call under the stage down limit adds a strike against the furnace.
- After the under target threshold count, the heat pump lockout is removed and the heat pump runs again on the next cycle.
Timings and thresholds
| Item | Value |
|---|---|
| Example target runtime | 20 minutes |
| Example stage up 20% | extra 4 minutes, switch to gas at 24 minutes |
| Example stage down 15% | furnace satisfying in under 17 minutes counts as a strike |
Applies to: Communicating or fossil fuel heat pump with gas furnace
More Goodman furnace sequences
- Normal power-up sequence · Startup
- Heating mode sequence of operation · Heating
- Cooling airflow ramping profiles A to D · Cooling
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Sequences of operation, error codes and tips work offline in the HVACopedia app.
Source: Goodman GMVC96 service and troubleshooting manual, p. 26-27, 32. 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.