I have a dual zone ad system in my house. It never had problems in the past, however today we switched it from heat to air. Everything worked fine until the thermostat was changed from cool to off

When this happened various rooms in the house lost power.

Thinking it was a tripped fuse I went into the basement and found that nothing was tripped.

Then I noticed all the rooms without power had gbic power outlets. None of those were tripped.

Getting frustrated I walked outside and looked at the ac fuses. They were good.

Not knowing what to do I randomly went back to the thermostat and click it back to cool and raised the tempature so the ac would come back on. When it did all power was restored in the house.

I then lowered the temp so that the ac would turn off and like before the power went out in certain areas of the house as well.

I flipped it back to heat just to see if it was something shorted and go the same results.

Now the only way I can get power is to leave it running all day.

Ideas?

This has to be one of the strangest problems I've heard. I hate to have to tell you this but troubleshooting a problem like this online is nearly impossible. I suggest you call an electrician who is also familiar with HVAC systems.

I had to do just that. I call in an electrician and discovered it was the line coming from the electrical box outside into the meter. One side of the line was pulling 102v and the other was pulling 203v. The meter itself had shorted out as well. The electrical company came out and had to dig up the line where it had gone bad just to replace it.

I tried everything I could think of from checking the thermostats to powering off one breaker at a time just to see what it could be.

Final words: before you go crazy googling the improbable, presuming you have the power to Google. Take a few minutes to check the meter outside. If its not working either call the electrical company.

Thanks for answering my dilemma. I had to do just that, I call in an electrician and discovered it was the line coming from the electrical box outside into the meter. One side of the line was pulling 102v and the other was pulling 203v. The meter itself had shorted out as well. The electrical company came out and had to dig up the line where it had gone bad just to replace it.

I tried everything I could think of from checking the thermostats to powering off one breaker at a time just to see what it could be.

Final words: before you go crazy googling the improbable, presuming you have the power to Google. Take a few minutes to check the meter outside. If its not working either call the electrical company.

Thanks!
David

This has to be one of the strangest problems I've heard. I hate to have to tell you this but troubleshooting a problem like this online is nearly impossible. I suggest you call an electrician who is also familiar with HVAC systems.

Be sure to check ALL appliances & especially ALL electronics. If any are not functioning be on the horn to the electric company pronto. If the trouble was on the incoming side of the meter, they should pay to repair or replace anything damaged.