Interesting response. I didn't think about the burst pipes thing. Thanks for heads up. I didn't think it would get that cold though. I thought it may get down to 50 max outside. Should've checked the forecast anyways though. I don't know what he did, but the heat started working properly after he left. It hadn't gotten over 65 according to the thermostat since I turned the heat up Sunday afternoon. Once he left the temp quickly rose to 75 where I wanted it. I should've known better to inspect the parts he was doing but at that point I was so cold and didn't want to look at what he was doing. He was on his hands and knees in the snow outside. I guess I will wait and see if the blower motor dies. I only started paying attention to the noise so I don't know if it's making a weird noise. Expensive lesson I guess. You're saying the p/n is not for the blower motor? I searched for the part it's giving me blower motors, but with extra letters/numbers. That is kind of odd since on the paperwork he also did put a gibberish serial number for my unit. It's like someone was just doing asdafadfhkaa across the keyboard. Worst case scenario how much am I looking at to replace the unit including labor? Are newer units more energy efficient as well?

Is this a window unit or central system? It could be a couple of problems but my guess is, the motor gets hot while running and when it shuts off, the residual heat causes the internal thermal overload to open. When it cools back down, the overload closes and the fan runs. The problem is either with the fan itself or a component in the fan circuit. There's a couple of things that could cause this. Without being there and hearing and seeing the issue, my first thought is the vents around the motor could be clogged with dust, preventing air flow over the motor. I've also seen mouse nests in them blocking air and adding resistance to the motor as it turns. If there is not enough air flow over the fan, it will heat up. Is your air filter REALLY dirty? You don't mention a squealing noise but resistance in the bearings could cause this. It could also be a capacitor. If the blower uses a start capacitor and that has gone, you would get the amperage draw you describe. Then it could just be the fan has lived it's life and needs to be replaced.

My question is, shouldn't the contractor have known the vent was too small when installing the unit? Yep and he should have known that 3 ton was too large also. Proper design is 400 CFM per ton and proper design for return is 2 CFM per sq in. So you would need return/supply design of 1200 CFM (which is too much for that sq ft), and a return grill total of 800 sq in (aka 20 x 40) I wouldn't want him to come back and do anything further, get someone else. Glad you got it covered, if parts are under warranty it is through the MFG not through the HVAC company. Perhaps a battery backup between the power source and the furnace is an option if somehow power outages are causing it. Maybe you are getting surges (or the blower motor is causing surges) and the battery backup would filter out the surges as well.

$1700 - insane. I can get the entire furnace $700. X13 You should have two speed taps for heat and cool, common 24v and the usual Black and White GRN to power the motor. X13 is ECM an motor.