View Full Version : Understanding transformer and circuit board
jj20
Sep 19, 2008, 07:08 PM
Good evening, I have a question. My ac has been out for the past couple of days. I just had a technician come to my house and fixed my problem. First, my ac was not working at ALL, I mean the fan will not come on or with ac- NOTHING was working. The technician used his handy voltage wiring testing and stated that my transformer was bad. After he replaced that he checked again to see what caused the transformer to go bad. He processed to tell me that my circuit board caused my transformer to go bad. QUESTION>> mind you my fuse is still in tacked and has not blown off, how can this happen? I thought that the fuse in the circuit board helps in not having your transformer go bad. CAN THIS BE TRUE? I just purchased a new transformer for 297.00 is this correct price? And now I have to purchase a new circuit board. Are they ripping me off?
acetc
Sep 19, 2008, 07:55 PM
It is possible to loose a transformer without blowing the fuse and if something is shorted out in the board such as a relay then yes this can happen, now then $297 for replacing a $15 dollar transformer is a little steep. If a componet part in your furnace such as a gas valve is shorted out then the fuse would blow and protect the transformer.
jj20
Sep 20, 2008, 01:05 PM
Thank you acetc for the information. So if something short in the board can cause the fuse not to be blown? Am I understanding correctly. So, in this case I would need to replace my circuit board? Once I replace my circuit board, can I use my old transformer? Or is this totally not useable?
hvac1000
Sep 20, 2008, 04:23 PM
Once I replace my circuit board, can I use my old transformer? or is this totally not useable?
It depends upon if the transformer is good or not. It can be checked with a meter to see if it will develop 24 volts on the low voltage side.