How much does it cost to replace a transformer on the heating and air conditioner?

Depending upon the unit but today's prices are high. Probably 50.00 for the transformer and with service call and labor another 150.00. I would think 200.00 might be today's number.

Mouser Electronics lists a Stancor P/N SWC-824 for $24.42 that puts out 4 amps at 24 volts. Likely you can find one for less than $50 at a hardware or home center. Just make sure the new one has as high, or higher rating than the old. A couple of screws and 4 wires to instal it. If the old one didn't have a fuse protecting it, I would add an inline one for a few bucks more.

No sense paying over $100 for labor for a simple little job. Such charges aren't a rip off, just the huge overhead in service work.

You were right on the money! Just had the transformer replaced today and I paid $195. The ac repairman broke it down to $130 for the part and labor and $65 for trip charge. He also flushed the line. One hour later I have AC... THANK GOODNESS with this summer heat.

Hello jeb1972, You comments were very helpful concerning AC Transformer installation. Are you able to share who you used to do the repairs? I believe, I have the same problem. Thank you.