We have a dual zone ac in our 2 story. It has been confirmed. But my question is will that cause us to have a large increase in our pg&e bill? Our bill has been astronomical now for 2 years. We've lived here for 3 years. Summer(2006) they had to come out and repair a leak in a pipe. A nail had penetrated the pipe.so is the cause of the ac problems the source of these electrical bills? Mind you pg&e has been out here several times and its not to do with anything faulty on their part. Someone please help me

Every ones utility bills are high and they are going to go up more in the near future. A dual zone system should not cause a great increase in usage if it is not working correctly unless you really do not want to heat or cool a part of the house. Your best bet is to get your furnace serviced by a qualified service person and at that time you might ask them what efficiency your furnace/AC system is.

If it is old you might consider replacement. The only problem with that is paying up front for the equipment but saying on the utility bill.