So I am trying to figure out my heater which keeps throwing a "Service System" error. I checked and it is the "PS" which I know is the Pressure Switch. I checked and it was not working properly so I was able to fix the switch and it pops up now and engages. But I still got the error. So I bypassed the switch and closed the circuit. Same "PS" Now here is where it is weird. If I open the HLS circuit with the PS circuit closed the HLS light turns on, but if i close the HLS circuit the PS lights back up. What do you think I should try next?