Trane X13i problems

Old 07-31-19, 08:47 AM
Thread Starter
Join Date: Jul 2019
Location: United States
Posts: 2
Received 0 Votes on 0 Posts
Unhappy Trane X13i problems

Hello. I am new here. Here is a little history on this issue. My daughter's 16 year old system started blowing the 5A fuse in the low voltage system. They then told me it was staying on after replacing it but was blowing hot air. I looked at it and the problem was they left the cover off in the attic so it was sucking hot air from the So we put the cover back on and the fuse blew. Replaced it again but now the outside unit would not kick on.
Took some measurements and had no 24vac at contactor. It had it before. Compressor and fan worked when I pressed the plunger and the line going into the house got cold. I replaced the contactor and cap. No change. I removed the wires from the sides of the contactor and side had 2 blue wires at 12v each when measured across the wire from the other side of the winding. 1 from the circuit board and the other from something attached to the copper tubing (pressure switch?) When I put the wires back on I hear a relay engaging and my voltage is dropped again.
This is weird...measuring across the red and yellow wires at the tstat I get a constant 28vac. Even when it is turned to off. I just ordered a replacement defrost control board just in case, although I don't believe that to be the problem. All of the major units are working, fan, blower, compressor, etc... The inside of this unit has been VERY well maintained. Looks almost new. Coils are all clean.
Any ideas on where to go next? Could it be a low pressure problem? Or a stuck switch? All ideas are welcome.
Old 08-03-19, 10:00 PM
Houston204's Avatar
Forum Topic Moderator
Join Date: Oct 2009
Location: Texas
Posts: 7,537
Received 38 Votes on 34 Posts
When heat pumps start popping low voltage fuses I usually suspect to O wire.
The O wire is usually orange.
This circuit is energized the entire time the thermostat is in cool mode regardless of cooling demand. The O wire can short to the hot gas line by the compressor or the O circuit can short due to a bad reversing valve solenoid.


The fact that you always have 24 volts between R and Y makes me wonder if you have a short.

You can remove the 5 or 6 low voltage wires to the outdoor unit and then replace the fuse to help prove that the short is not in the outdoor unit.

Thread Tools
Search this Thread
Ask a Question
Question Title:
Your question will be posted in: