So tested both and neither has continuity. Basically the pressure switch has four wires. Two come from the panel and go to the pressure switch. The other two from the pressure switch to the flow sensor. There are only two connectors on the pressure switch each receiving a wire from the flow sensor and the panel connected in parallel. Check the drawing that I made.

I tired adjusting the dial on the pressure switch but the only time I would get continuity was when I touched the wires from the flow sensor. I take it I have a bad flow sensor but does the pressure switch itself do anything other than have a dial on it?

One last thing about the flow sensor. If I pressurize it by blowing air into it I get continuity which now makes me wonder if it's just the circ pump not creating enough pressure.

This post was edited by bandito on Sun, Apr 20, 14 at 11:44

I replaced the main pressure switch on the tube. I set it to the lowest PSI, same problem occurred. I then set it to 2 PSI which is factory spec. Better but the problem eventually occurred. I disconnected the pressure switch for the circuit pump so the only switch connected at the moment is the heat tube one. Runs like a charm. Question..how important is the pressure switch for the circ pump? Do I really need it it?