I have a Goodman 4-ton heat pump that the air handler varispeed fan runs 24/7, The t-stat is set on auto-heat it is a ssz140481a unit with a AEPE 42601 air handler - it is hooked to a honeywell TH300 Series t-stat

A heat pump on the optimal heating day (about 50 degrees ambient) will only deliver approximately 85 degree air as compared to 125 degree air from a fossil fueled furnace. The colder the outdoor air is the less heat there is available to be transferred to the living space. At 30 degrees, the heat transfer capability is getting close to negligible meaning the run cycles will be approaching continuous and eventually as the heat pump along cannot maintain setpoint, the outdoor stat or stats will bring on auxilliary heat in the air handler.

If your ambient temp is below the 'balance point' of the heat pump, the house temp will drop a little lower and most times energize the heat strips through the outdoor t-stat. Your outdoor stat could be set too low for the heat pump to carry the structure all the way down to the balance point so when you turn it off and back on, the lower indoor temp automatically brings on the heat pump plus a heat strip or two, thus the warmer air. Second stage on the stat satisfies due to the heat strip, drops them out of the circuit and the heat pump is left running on first stage heat delivering the perceived cold air.

Your outdoor stat could also be not functioning correctly and not allowing the heaters to come on until the system is turned back on reestablishing the two stage call for heat.

Tons of possibilities and not enough room to list....

If you look on the install manual. It says it will work for a heat pump without backup heat. No heat strips.........If you do not have strips the guide says as follows

"PLACE A JUMPER (PIECE OF WIRE) BETWEEN Y AND W IF YOU ARE USING A HEAT PUMP WITHOUT AUXILIARY/BACKUP HEAT." if this dosnt work check the fuse in the air handler you may have blown it if you did not turn the unit off before installing.

check your themostat fan mode switch to see if it in on or auto. It should be in auto. If this does not stop indoor fan motor, (it may take up to 2 minutes for the fan to stop, preprogrammed shutoff in the thermostat and fan control cards may make you think the fan has not stopped ) If this does not stop the fan the fan control board in your air handler has a green wire shorting to 24 volt signal in the theromostat wire or the contact on the blower control card is stuck and will need replaced.

the fan fill come on with the sequencer (stack switch you call it) it will also come on with the fan relay. on some goodmans the fan relay is the black box on the circuit board. use a jumper to jump red to green, this should bring the fan on sounds like you could have a broken green wire, try using a different wire instead of green

Dont know what equipment you have but yes of course there is a fix. Turn power off to air handler. cycle power to heat pump and be sure the board is configured properly to match your outdoor unit. Then turn power on to indoor unit and likely go through system setup once again. provide model numbers of all communicating components if more problems.

If you need further help, reach me via phone at https://www.6ya.com/expert/thomas_092728000e6acb79

It can run 24/7 if you want it to but doesn't have to...although it creates a more uniform temperature in the house and maes the AC more efficient in the summer...There should be a switch on the thermostat for "Auto" or "Manual"....Auto will turn the fan off and only come on when Heat is required...manual will make it run 24/7

Heat-Pumps can be temper mental. Sounds to me like your air handler is running on emergency heat, due to a problem with the condensing unit.You have heat strips in the air handler in case the outdoor temp. gets to cold and the heat pump cant keep you're home warm.Also, if you loose a compressor, it will go into emergency heat. If you have lost the compressor for one reason or another, lets say a locked rotor, the compressor would draw L.R.A. (Locked rotor amps) and cause the circuit breaker to trip. Check this.As for the air handler running all the time, you said you replaced the stat? When you removed the control wiring from the stat, did the fan shut off? I wish I were on site to help you, but all I can do is offer you some advice. With the power off to the air handler, go to the stat and remove the red and green wires. Turn power back on and see if it stops running. If it stops, then it sounds like the new stat is also faulty? If it continues to run, check the wiring in the air handler to make sure the red and green are not touching somewhere, and also check the control wiring on the outdoor unit for the same problem. Do you have any dogs that may have chewed into wiring? If so, check all outdoor t-stat wiring. There are so many things it could be and I hope very much I have helped you with solving this online, which can be difficult. You may also have a faulty defrost board. Try to do what I have asked of you.
Good Luck, Sincerely, shastalaker7

is this a new problem? the fan speeds can be adjusted by changing wiring connections. If it is a new problem on an existing system then it could be the t-stat or a problem with the curcuit control board. the switch on the t-stat for FAN is set to auto not ON. if set to on the switch to auto - problem solved.

On your t-stat you have Y, W1, W2, R, O, G, B or C or X. Y is your cooling circuit and will be the same in the air handler and heat pump unit, use the yellow wire for this circuit. W1 and W2 are your back up elec. or gas heat. Depending on how many kws or heat strips you have and t-stat wires you will put the white wire to W1 in both the t-stat and air handler. W2 is for your second stage back up heat if air handler calls for it, this will be a tan or brown or black t-stat wire and goes to W2 on t-stat and air handler. R is half of your 24v control power from the transformer and is the red wire and goes to the t-stat, air handler, and heat pump. O is for the reversing valve in the heat pump that switches it from heating and cooling. You guessed it the orange wire connect to t-stat and heat pump. G is for the blower and is the green wire to the t-stat and air handler. B or C or X is known as the common which is the other half of control circuit from 24v transform it is the blue wire and goes to the t-stat, air handler, and heat pump.

do you have a totaline t-stat. they and some other brands have a fan recirculation setting in the installers menu.

this is assuming that this happens in addition to the heating or cooling normally