The house I live in has fan-forced heating that consists of a fan blower and a gas heater. When the thermostat goes on, the fan and gas unit turns on. If the circut for the fan blower is cut off when the thermostat kicks on and the heat is supposed to be on, will the gas unit burn out because the fan isn't blowing?
Some space heaters have accessory blowers or fans that can be added but are not required. It is not clear from your description weather you have this type or a typical forced air furnace that has duct work attached. A forced air furnace needs airflow or the burners will cut out shortly after the burners come on due to limit switches that detect overheating.
No, they have high temp cut off. Repeated tripping of high limit will make high limit switch go bad. Fix fan, I doubt you'll get much heat without it. Check fan most have three speeds. Try switching wiring to unused speed sometimes if a winding goes bad the other speeds will work. One speed for heat one for AC and one unused. No ac 2 unused
I'm not sure but I believe modern ones have thermal interlocks on the gas. I wouldn't trust that, though, particularly on older units.
You may have a bad capacitor,many units use a dual purpose one that powers both the fan and the compressor. Much of the time when these fail the ends will pop up like a bad can of beans.Other times oil will run out of them. This is a silver round can type thing with wires coming out the top.It is in the electrical panel on your outside unit.Be care full not to touch the wires or terminals it can shock you.Pull the disconnect to the ac before servicing. Most ac or appliance shops have these ,cost 10 to 15 dollars.MORE INFO. If the drain was the problem you would not hear a hum as it would not send power to the outside unit.The capacitor terminals are marked with letters,make a drawing of what color wire goes where.Again remember to turn off or pull the disconnect,the box on the side of your house close to the a-c.unit.Use plastic handle needle nose pliers to remove wire's and do not touch the terminals on the capacitor after removing it can still shock you.Take this to the appliance shop and they will have one and can give advice.This is the most probable cause.The other less likely causes will require an hvac tech to repair.
I will try and explain how a gas furnace works. When there is call for heat, your Thermostat will put 24volts to the furnace. Heat will then kick on. when the heat exchanger gets to a certain temperature then the fan will kick on. After the room temperature is satisfied it will kick the heat off.The fan will run for approx. 30 seconds all the way to 5 minutes. The reason the fan stays on is to make sure all the heat has been removed from the heat exchanger. If at anytime the fan does not kick on the furnace will go off on what is called high heat. There is a safety device that is in the furnace called a high limit switch that will cut off the gas supply and turn the fan on. By turning the fan on, It will help cool off the heat exchanger to keep it from getting damaged. If the fan circuit is not working then I would have it fixed. The high limit is only a safety device. They have been known to fail causing damage to the furnace. You will need to have it fixed. A cracked heat exchanger is a major cause of carbon monoxide poisoning. Not a good thing to have. I hope this is the answer you are looking for. Good luck
