my home ac unit is blowing warm so had a company come out and look at it. they said the condenser fan motor bearings were shot. I declined replacement but after he left I went on the roof to check it myself but did not notice any looseness or grinding when i spun the blades. How would tech know? would this cause it to blow warm it is a heat pump rooftop unit.
The only way you can tell without investigating is by sound or seeing the the fan wobble, It could be just a little. Unfortunately replacing the bearings would not be a good idea. Actually you could have a collapsed ductwork in the attic.
Not really sure what Your talking about, the details you gave are not exactly clear and why would you turn him down unless you did not think he was trust worthy.Yes if the fan outside is not running the unit would not necessarily blow warm air it would blow room temp air. If you go to start the unit and the fan comes on it's ok. if you spin it and it spins freely it can still be bad just not as likely. I am wondering if the compressor is even starting. when you turn the t-stat on grab the thinner of the to line see if you should feel refrigerant running threw it, if it is you will feel it and if the fan is not running it should get hot fast(The thinner copper tube going from the outside unit to the inside). The problem could also be the capacitor. What i would do is find a company you can trust you need to have a good tech look at this thing, either call the manufacture and ask them for a good company in the area, ask people in your area chances are they have used a company before, or look on the net and when you checking them out look to see how long them have been in Business, or even check the better Business bureau.
The service call is generally a 'no cool' call when it comes into the shop, and there are ten things to check to diagnose the no cool problem, more on a h/p, so determining that the blower motor is THE cause isn't very common at all. Better call someone else. The motor test is seeing if the shaft spins freely, does not have a lot of up and down movement and then measuring the volts and amps, with a multimeter, while running. The amperage draw if higher than the run load amp will tell you the condition of the bearings and/or windings. You test the capacitor, too. And the wiring connections. Also, look at the blower wheel. Besides, a problem with the motor that slows down the rpm's and lowers air flow will deliver less return air across the evaporator, which will decrease it's temp from 40 degrees to possibly near freezing, and deliver colder air, not warmer. So the problem is something else. The most common is dirty coils, filters. Then leaks. But, they will have to check the pressures and temps, and see what those tell you and then go from there.
best way to check bearing is to take the condenser fan motor (with power off and double checked with a meeter) have the moror sitting with shaft up. hold the shaft and move it side to side. it wont be visible usually but if you feel any give in the shaft then the bearings are bad. However many use the word bearing loosely as many condenser fans use sleeves instead of bearings (cost of manufacturing). The smallest ever so slightly feel of play can show warn or bad bearings or sleeves. I have seen condenser fan motor with bad bearings that passed this test and ran normally until they got hot just as I would about give up on it and when they got hot they your start to slow down or sequel. With most of the motors now days it better to replace the whole motor than just the bearings. If you do not trust your tech then call somebody else. I recommend having a N.A.T.E certified technician as they have higher certifications. also when you call the company ask if their techs are paid hourly, commission or piece rate. many HVAC company's now days are paying their employees on piece rate which means the more parts they change the more they get paid.
