HVACopediaKeepRite · Furnace · Cooling
Furnace blower with outdoor A/C: cooling, dehumidify and continuous fan
What happens, in order
- Single-speed cooling R-G-Y starts the outdoor unit and the blower on cool speed; air cleaner terminal powers with the blower
- Two-speed cooling Y1 runs low cool (outdoor unit low, blower at low-cool speed); Y1 plus Y2 runs high cool
- Thermostat satisfied outdoor unit stops and the blower runs 90 s more; jumpering Y/Y2 (or Y1) to DHUM cuts that to 5 s
- Dehumidify (humidity thermostat on DHUM, logic is reversed so 24 V present means no demand): low cool keeps the low speed; on high cool the blower drops to a lower speed for up to 10 minutes then returns, cycling in a 10 minute pattern for as long as cooling runs (9MAE reduces airflow to 86 percent instead)
- If DHUM stays low for more than 48 hours the control goes back to ordinary thermostat mode
- Continuous fan R-G alone runs the fan speed; during a heat call it stops through igniter warm-up, ignition and the blower-on delay, then returns on heat speed; after cooling ends it runs the 90 s cool off-delay before returning to fan speed; when R-G opens it runs 5 s more if nothing else needs it
Timings and thresholds
| Item | Value |
|---|---|
| Cooling blower-off delay | 90 s (5 s with DHUM jumper) |
| Dehumidify blower step-down | max 10 min |
| Blower-off after G opens | 5 s |
| DHUM timeout | 48 hours |
Applies to: KeepRite / ICP (F-G)9MXE single-stage 95% furnace (KeepRite G9MXE); KeepRite / ICP (F-G)9MXT two-stage 95% furnace (KeepRite G9MXT); ICP (F-G)9MAE modulating 95% furnace
Models
More KeepRite furnace sequences
- Modulating 95% furnace: ignition sequence and retries · Ignition
- Single- and two-stage 95% furnace: ignition sequence and retries · Ignition
- Modulating 95% furnace: adaptive heating, staging and blower delays · Heating
- Single-stage 95% furnace: heating cycle and blower delays · Heating
- Two-stage 95% furnace: low/high heat, staging and blower delays · Heating
- Furnace used with a heat pump (dual fuel blower timing) · Other
Take it to the job
Sequences of operation, error codes and tips work offline in the HVACopedia app.
Source: KeepRite/ICP (F-G)9MXE service manual 440 04 4311 09, Sequence of Operation / KeepRite/ICP (F-G)9MXT service manual 440 04 4321 10, Sequence of Operation / ICP (F-G)9MAE service manual 440 04 4700 00, 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.