Over the past few hears our ac/ heating unit will work when fixed by someone for a couple of weeks at the most then quit working. My husband has tried to fix it as well as other electricians but they do fix it but it only lasts for a few weeks then quits again and we are left with no air conditioning during the summer or no heat in the winter. We have two units in oour house. The other one heats the den and one bedroom. It works perfectly. What could be wrong with the bad unit. We just got it about 5 years ago. Please help me so I can know what I'm talking about to the electricians. This one electrician is very trustworthy, I know him personally. He is coming back today to work on it. I don't know what he did to make it work again a month ago but it only worked for a week then quit suddenly. Please any advice to help me with this would be greatly appreciated.

What exactly have they done each of these times? That way we can guess what is repeatedly failing. And if we know what we might be able to guess why.