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Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 6022
Experience:  Retired HVAC/ Electrical & Boiler contractor. Industrial
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I have a Trane UDO80R9V3K. The gan is not going on, there

Customer Question

I have a Trane UDO80R9V3K. The gan is not going on, there is water/condensation leaking, and the LED on the control board is on indicating it needs to be replaced. The local tech hypothesized that the blower motor is bad causing condensation to build up and leak onto the control board causing it to fail. They want to replace the control board and motor $1500 in parts plus labor.
Submitted: 2 years ago.
Category: HVAC
Expert:  Phil replied 2 years ago.
Hello, a bad blower motor will not cause water to build up in the cooling coil and so that it leaks down through the furnace and onto your control board... it will cause the coil to ice over though, and when the ice melts water can drip down over the control card etc. If the blower runs it is fine and does not need to be replaced... let me know if you can get it run by setting the thermostat FAN setting to ON. The model number you gave does not compute, did it come from a sticker inside the gas valve compartment that also shows the serial number. that will be the place to get the correct model number. If the blower does not run with fan set on Fan ON, it could very likely just be a bad fan relay on the control card and not a bad motor. Tell me if this blower is variable speed (starts and stops very slowly and quietly) or if it tends to come on hard or not... that will tell me what I need to know about the pricing. We can go from there.
Customer: replied 2 years ago.
The number on the sticker is TUD080R9V3K4. There is a second number 7082P161G.
The blower does not come on with the fan set to on. It is a variable speed motor. I pulled the motor and checked all the resistances. They seem fine. I'm not sure how to check the ECM. My thinking is to replace the control board and then plug in the motor and see if it works. The control board is definitely bad. Of course none of the local distributors will sell to a consumer so it doesn't look like I can fix it today.
Expert:  Phil replied 2 years ago.
Hello again, you are on the right track.Look this video over for the most common failures in these end bell speed controllers me what you find on your motor. Lets do that first, and go from there. Please hold your rating until we get the situation entirely resolved.--------------We are on the honor system here. Please remember to rate my service before you leave today. If you need anything else, just let me know. You can continue asking follow-up questionst at no additional charge.