If your fan does not come on in the on position, then you could have a different circuit breaker for the fan motor. If your AH has a PCB, is any lights on? Open the AH and smell the motor. Does it smell burnt?

That airhandler has a low voltage fuse in the control box to protect the transformer.Looks like a car fuse.The only circuit board it has is a time delay built onto the fan relay.Make sure there are no breakers at the airhandler.If you loose power to the indoor unit nothing will run.You will have no low voltage for controls.

I had an HVAC person out today. Turns out that the electric lines that feed into the breakers on the air handler have a short in them. He showed me how the wires that feed into the breakers are burnt in spots. Since there is no extra wire to cut off the bad spots and rewire them into the breakers, he said that an electrician would have to run new lines (vs. trying to splice new wire to the end of the existing wire) using a higher grade line than my current lines from the circuit breaker box to the air handler. Once the wire is changed, the HVAC person said he can come out to replace the breakers on the air handler and connect up the new wires. I have to get a hold of an electrician to get a quote to do this job but my HVAC person warned that this would likely take an electrician a good half day or so to do. Hopefully the quotes from electricians aren't too bad considering this is a 13 year old system and I don't want to begin having it "nickel and dime" me. If the quotes are very high, I may think seriously about getting a new system. Does it seem reasonable to have to rerun new electric feeds vs. splicing? Is there a potential that this problem could damage something else beyond the breakers in the air handler?

Got a couple of quotes from electricians and to get things up and running isn't too hateful. But one of the electricians brought up a good point/question. The electrician said that the wire that is currently in place is more than rated to handle the load since it's a gauge 6 copper line already. His biggest concern was that if there is another problem that is causing the wires to get hot that doesn't get fixed, that the ends could fry again. I definitely can see his concern there especially since I don't want to be plunking down a few hundred dollars all of the time to get things fixed. Does anyone have any idea what could cause the wires going into the air handler to get hot and fry?

s012adh,with all my years in the field I have seen that same problem many times.9 out of 10 times the wires melt because of loose connectiions,termination lugs at the heat strips .Very rarely is it a problem with the apliance itself.We frequently go back to new construction systems where the electrician did not tightnen the lugs on breakers feeding our equipment causing them to trip.If the incoming wire feed is correct size and all lugs and screws are tight you should not have a problem.Make sure to check amperage on the incoming feed also.

Is it common for it to take a long time for wires to begin to melt? My air handler is 13 years old and I would have thought that if the connection was loose in the beginning that it would have caused a problem long before now? Does the lugs have to be noticeably loose to cause a problem? I checked the wires going into the breakers and they seem snug.

I have this type of heat pump as well and I think I did a boo-boo.

The system has been working fine for 10 years. Recently, I took adjusted the faceplate of my thermostat (Honeywell CT3611) and as I was reinstalling the faceplate of the thermostat, there was a little spark.

After that, there is nothing on the LCD display of the thermostat.

The only thing that seems to work is the air handler fan kicks on when the Fan setting is set to "ON". Nothing in "Auto". Neither heating nor cooling seem to be working.

Does this sound like I blew the thermostat? The other components that seem to get blown like this are a fuse on the air handler or a transformer on the air handler.

I'm hoping I just blew a fuse. Can someone tell me where to look for it on the air handler? If it is anything more complicated than replacing the fuse, I think I'm going to have to call in an HVAC person.

Thanks for your consideration.

David

if the fan comes on, then your transformer is working, mostlikely, you blew something in your electronic thermostat, or you connected a wire wrong somewhere. my bet is the spark you made, took out a component in the thermostat. the fan is a mechanical switch in the thermostat, so no electronics are required for it to work.

In looking for a new thermostat, I've found a TH8321 locally.

The wiring seems a little bit different, though.

Can this be mapped to my wiring?

My current wires are:

G O Y W1 E W2 R C

The TH8321 has these marked terminals:

L E Aux S1 S2 RC R O/B Y G C

Thanks for any tips.

I got my system (Trane XE1000 Heat Pump with Aux. Heat) up and running with the new thermostat. While the aesthetics are much better and the programming is much easier than my old thermostat (CT3611), one thing that I noticed this AM is that this thermostat seems much more likely to kick in the Aux Heat.

I have a 2 system house with a gas furnace in the basement. I'd like the heat pump to be much less aggressive with turning on the aux heat and rely a little more on the gas furnace to help bring the temperature up in the house.

I found a setting (580 or 680) which states adjusts an "aggressiveness" factor for the aux heat but it still seems to kick on quickly.

My old thermostat had a feature called something like adaptive heat recovery which calculated how long it took to heat the house back up and adjusted itself to just turn on earlier if it takes longer to warm the house. Granted, I didn't sit around the house all day watching the thermostat to count the hours the aux heat was on or off, but it seems like it was less.

Does this new thermostat do the same thing in terms of trying to minimize aux. heat use? Is it just a matter of time before the thermostat learns my house and heating patterns? Does having the external temperature sensor help?

Thanks,
David

We have had this heat pump since 1991. Last year it stopped defrosting. We had our service man come and look at it. He replaced the board three time and it is still not working a year after this started. He says there is a problem with the boards that are made now (in China)and that they do not fit well so they do not work. Has anyone else had this problem?? If so, what did you do?

My Trane Model# GUCDA-08-A Type 174-467-1-A is more than 20 years old and worked like a charm until last month when it suddenly stopped working. I paid a Trane service man $79 to come by and check it out. He said it was the motor and wants to charge me $750 to replace the motor, or get an entirely new HVAC system. I called the gas company, and they sent over a service man (free of charge), who recommended that I check the limit switch. I like my Trane and really believe that the problem is a simple fix, but I just don't know. What is your expert suggestion?