My furnace heats the house well, but during the cool down it actually blows cold air dropping the temperature causing the furnace to re-ignite. How do I adjust? Goodman - GMS9/GCS9

The fan relay is stuck in the on position. When the temperature drops the heater does not ignite because the fan is already running and ignition is locked out after the heat cycle starts an the fan turns on

If it's a 90%+ gas furnace, check the combustion air pvc pipe for blockage, if not enough air for proper combustion, control board will shut down the flame to keep from burning poorly! Check your air filter, there's an overtemperature safety switch in the heat exchanger to protect the furnace/ your house, and low airflow will cause the heat exchanger to overheat. Finally, check to see if the flames actually ignite, if no flame, the controller will reset and try again, then if no flame, the controller will reset and try again, then if no flame, the controller will reset and try again, then if no flame, the controller will reset and try again.... get the idea? :) If this is the case, check my other solutions, I just answered someone elses question about non ignition. Hope this helps.

se this fact: God bless you
air conditioning system cools but does not dehumidify the room. The most common cause of inadequate dehumidification by an air conditioning system is the installation of a cooling unit which has too much capacity, or is "over-sized" for the space it is being used to cool. What happens is simple:

If an air conditioning compressor unit is oversized (too many BTUH of cooling capacity) what happens is it cools the room so quickly that the system does not move enough total volume of air across the cooling coil to remove much moisture before the room temperature has dropped to the A/C cut-off point.

In other words, an air conditioner needs to run longer, and move more total volume of air through itself to drop room humidity than it does to just cool the air. So "bigger" cooling capacity or higher BTU capacity for an air conditioning system is not necessarily better, and it can actually be a problem.

If it always shuts down during the night it could be an air adjustment, during the nighttime the humidity and temperature both drop making the air denser with oxygen and "can" cause the initial light off to be so lean that the flame does not fully ignite. If there is an air adjustment move it (slightly) to a smaller number reducing the amount of combustion air which richens the mixture of oxygen and hydrocarbons (fuel). A rich mix will light reliably, too rich and you will make soot during burner operation so if the trick works more is not better, don't soot up your furnace or vent pipe by going too far.

It sounds to me that your air flow is restricted somewhere. The first thing to check is your air filter. If that gets real dirty your restricted air flow will cause the hi-limit(hi temperature limit switch) in your heat exchanger compartment to over heat and open up your gas valve electrical circuit,thus, shutting off the gas to your burners. After the hi-limit switch cools down the furnace will go back to heating again then it will overheat again(you get the picture?) If it keeps cycling on and off like that the house will never get warm if it is cold outside. If your air filter is reasonably clean(you should be able to see light thru it easily) then the secondary heat exchanger could also be dirty, this is located above the indoor fan housing, you would need to pull the indoor blower assembly out of the furnace and look up above. The secondary heat exchanger looks similar to a radiator will fins. You can use a medium stiff plastic brush to brush the dirt,hair, whatever off of it. Another problem spot would be the cooling evaporator coil (if you have central airconditioning) located most likely above the furnace in the plenum(if your furnace is in a basement). This usually is difficult to access if an access cover wasn't installed when the airconditioning was installed. I would recommend an experience service tech to clean it for you. Also make sure all you supply air registers and return air registers are open . These are the things I would check first. Good luck!!

the fan you hear come on at a call for heat is most likely just the inducer motor. the click you hear is probably the relay for the hot surface ignitor which should glow red, then in turn ignite the main burners. your going to have to determine if the ignitor is coming on. if it isnt the ignitor is bad and will need to be replaced. if it comes on and than shuts off after a few seconds the ifc board is probably at fault

Yes. The defrost cycle of a heat pump is actually turning on your airconditioning to heat up the condenser to thaw it out. During this cycle your electric strip heaters "should" be adequate enough to compensate for the a/c being on. At about 30 - 34 degrees outdoor temp there is not enough heat in the air to to adequately heat your home with the heat pump only. Some technitions will use an outdoor thermostat to turn off the heat pump when it is under 34 degrees outside. If you are to cold when its under 34 degrees intall more electric strip heaters.. But if you do this your electric bill may go up significantly.
Welcome to the wonderful world of electric heat pumps (lol).
Good luck.

69,000 btuh is adequate for a 12-1400 square foot house.
Otherwise, your thermostat simply tells the furnace to cycle on/off.
If it calls for heat and does not come on, the problem is with switches and relays within the furnace.
Your setting the temp higher only causes the other parts to keep trying until they finally light and heat.
This is based on your information saying it will cycle on and blow cool air--not hot air.
You will have several temperature variations from floor to ceiling.
You probably have ceiling vents as well.
You need a technician to verify the rollout switches, fan relay, inducer fan etc. if the furnace is not firing everytime you call for heat.

Make sure a back draft in the flue is not happening. Wind can blow it out until the flue heats up. The flame sensor may not be close enough to the burner flame. It may be weak and need to be replaced or if its an optical one it may be dirty and not see the flame very well. Its not wasting much gas but it puts extra wear and tear on the gas controls, is noisy, and, as you said, blows cold drafty air. A gas control system that has issues of any kind is not real safe. It needs to get fixed.

Sounds like you have a problem upon start up of heat. Your safteys maybe shutting you down, and restting voltage to your curcuit board allows you to have another heating cycle. Honestly you may due justice calling a tech.