This system pulls hot water from my gas hotwater tank into a copper coil in the electric airhandler, and then air blows over it to heat. It has worked fine until my hotwater tank had to be replaced. I had it "professionally" done - same 40 gal size. The heat works, and I can take a hot shower, but not at the same time...!! I have to go out to the tank and switch the ballcock valve on the copper pipe so water it is not going into the airhandler. There doesn't seem to be air in the line, as both systems are working. I contacted Aquatherm, and all they said was new tanks have a heat trap on top with plastic pieces inside. I should open it and take the pieces out!! I've looked at the tank, and don't see a noticeable galvanized pipe at the connections. My "professionals" have been out 3 times with no luck, and now they are researching the problems...!! This means I probably won't hear back from them!! Any help, thoughts, suggestions will be greatly appreciated. Thanks, Amanda J.