When I blow into the PS it clicks, but as soon as I stop blowing it clicks again. When the thermostat calls for heat there is a slight humming. The heater is definitely trying to do something. After a few minutes the lights start flashing twice again. I hope this answers your question, if not please...

About a year ago our heater stopped coming on. Through lots of research and trouble shooting we were able to figure out that the pressure switch was stuck closed. If we unhooked one side of the switch and blew into it, the heater would magically work (Of course the heater was disconnected from power...