Furnace is shutting past its sell-by date hasty and still blowing cool nouns.? Hello, I have a Trane XE80 (14 years old) that periodically shuts the...
Hello,
I have a Trane XE80 (14 years old) that periodically shuts the gas past its sell-by date but the blower continues to blow trying to heat the house up. If I shut the furnace rotten, allow it to restart, everything will work fine for a few hours or days. So the occurance is random.
Some milieu info. About a month ago we had a "shister" repair tech come and diagnose our furnace for what appeared to be a unpromising blower fan motor. He said it be bad and that the boil exchanger was cracked, but told us if he fixed it ($1193.00 motor only) we should be ok for while. I get rid of him, and got another tech. It concluded up only anyone a bad capacitor ($12.00), however the motor be squeky and we determined that the motor shaft was getting loose. We replaced it also ($170.00). So, I am concerned if the first repair tech sabotaged the furnance.
My individual other thought is the temperature sensor is getting to hot and is shutting the gas sour, but I should see the gas turn back on once it cools down.
Answers: Maybe by knowing how it works you can amount it out on your own. The wall thermostat fires up the gas valve.It does zilch else. The heater have to get hot first and next the fan/limit senses the heat and when it get to Xdegrees it fires off the blower motor. The home get to the desired temperature and the wall thermostat shuts down the gas valve(no more fire) The remaining fry in the chamber get blown out and the heater cools down, The fan/limit senses the metamorphose in warmth and shuts off the blower. So what can shift wrong? The twisting bi-metal inside the fan/limit can hang up over time and preserve the blower going although the heat chamber have long since given off its ending little bit of heat. As a result it is in a minute blowing out cold air into the house and annoying the residents. Remember the wall thermostat does not controll the follower EXCEPT if you switch it to MANUEL from AUTO. I have be to homes where the children hold accidentally moved the AUTO lever to Manual and the fan runs continuously. In your grip that would be an easy fix. I doubt it though. I would say-so you need to replace the fan/limit. By the road why call it a fan/limit? Well when the fire comes on and the kiln is warming up the bi-metal verbs begins to slowly rotate towards the enthusiast switch. When it hit the fan switch the blower comes on and the thaw out air comes out, but what IF the blower motor one-time to come on? Uhoh! the fire is still on! the heat is building ! the stove will catch fire! the house will burn down, BOOM! the restraint shuts down the fire! as the bi-metal carrys over PAST the fan switch it gos to a point where on earth it is too hot in the chamber and it shuts down the gas stopcock. But what if the fan bound failed to shut down the gas spigot? Then a ceramic fuse mounted within conjunction with the pilot assembly will unfreeze and kill electrical current to the system. The gas will shut down. the bake will go away. Along near the melter their are at least 4 popout switchs call roll out switchs. One is in the stack and measures exhaust temp if the exhaust is blocked it will popout and assassinate the fire. their are 1 on each side and one below too.Roollout occur when the burners are blocked with rust and the flame single lights on parts of the burners. The resulting pooling effect of the gas goes POOF! and get on yer nerves. It can cause the furnace to malfunction. $1193 for a lover motor is a rip off and this man requests to be reported to the better business bureau.
First you should check the air flow. This can be done by checking the warmth rise. If that is usual, the fan/limit control could be going bad. For more info including a step by step troubleshooting guide, check out the furnace page at my source.