I have an American Standard Freedom 90 gas furnace. On heating days it seems to run almost continuously. After the initial morning warmup, the unit will come on and run for 5-10 minutes, be off for 5-10 minutes, etc. etc. I notice on the thermostat (American Standard ACONT800) that the temperature never varies from the setpoint (70 degrees). That is, there does not seem to be any bandwidth...the furnace holds the house temperature at 70 and does not let it fall a degree or two and then warm it up again to the setpoint temperature. Also, I know that this furnace has a 4-speed blower, but the furnace always seems to operate in the two high speeds and never in the lower speeds.
Does anyone here know if this sounds like proper operation for this system? Thanks!
That stat is not suppose to let the temp drop more then .5°F from set point. And since it rounds out the display temp. You shouldn't see it drop or increase on the display.
The CPH might be set too high. And a lower setting would get you longer on and or off times.
If your furnace is a 2 stage. and they are using that stat. they have used not the wrong stat. But not the one they should have. Should have been a ATON802 or 803. Then the stat would control if it runs in stage 1 or 2.
The blower speed should be set for proper temp rise. And it will only be 1 of 2 speeds for heatng. While cooling can be a different speed yet.