PROGRAMMABLE COOL FAN-OFF AND FAN-ON DELAY.
(Installer table steps 7 and 8.) These items allow a selection of 0 to 127 seconds of fan-off delay after the thermostat has satisfied the call for cool, or a fan-on delay of 1 to 30 seconds on a call for cool (or heat pump compressor activation).
The fan-off delay allows the fan to continue running after the compres- sor has shut off. This distributes the cool air that would otherwise stay trapped in the air conditioning coils through the ducts. Ideally the timing would be set so the fan shuts off just as the cool air is exhausted. If this timing is set too long the fan may begin blowing warm air before it shuts off. Shortening the fan-off delay will prevent this.
Ashort delay to allow the A-coil to cool off (or warm up in heat pump) before the fan turns on may be preferred. This also allows the compressor and the fan to come on at slightly different times, which allows full power to the compressor on start up. Recom- mended setting for fan-on delay is 10 seconds or less. A system that does not have a high head pressure cutout should have a delay of 10 seconds or less.
PROGRAMMABLE HEAT FAN-OFF DELAY.
(Installer table step 9.) This item allows a selection of 0 to 127 seconds of fan-off delay after the thermostat has satisfied the call for heat if ELECT HEAT FAN (Step 3) is selected ON.
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The fan-off delay allows the fan to continue running after the burner, heating element, etc. has shut off.
This distributes the heat that would otherwise stay trapped in the ducts. Ideally the timing would be set so the fan shuts off just as the warm air is exhausted. If this timing is set too long the fan may begin blowing cool air before it shuts off. Shortening the fan-off delay will prevent this.
PUMP (FOSSIL FUEL KIT ALTERNATIVE).
(Installer table step 10; heat pump only) This item controls heat pump compressor operation with a fossil fuel auxiliary. This menu item may eliminate the need for a separate fossil fuel kit, although we recom- mend that you consult the heat pump system manufacturer before