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Thermostat control

bufordtputtsbufordtputts Posts: 2Member
I have a new Bosch Greenstar FS with a FW 200 controller. I have an issue that when my thermostat calls for heat, it doesn’t turn on the pump or boiler. I used a multimeter and I have 22 volts across the lines. I noticed even when the thermostat inside the house is turned off, the pump still runs like there is a call for heat. Is there a programing issue with it or something else going on?

Comments

  • HVACNUTHVACNUT Posts: 1,590Member
    > @bufordtputts said:
    > I have a new Bosch Greenstar FS with a FW 200 controller. I have an issue that when my thermostat calls for heat, it doesn’t turn on the pump or boiler. I used a multimeter and I have 22 volts across the lines.

    Wher do you have 22v ?
    If the thermostats is calling, the thermostat terminals at the Boiler should read 0 volts.


    I noticed even when the thermostat inside the house is turned off, the pump still runs like there is a call for heat. Is there a programing issue with it or something else going on?

    No boiler or circ when the thermostat is calling, but the circ runs when theres no heat call?
    Does the burner also fire at that time?
  • bufordtputtsbufordtputts Posts: 2Member
    Well I put one probe on the red wire and the other on the white and I got the 22 volts. I got the same when I tested the terminals on the boiler. I wanted to make sure that I at least had power. When I put the two wires together as well, the pump and boiler wouldn’t turn on. They are supposed to turn on together which they do when there is a call from some other source other than the boiler. I believe the call is from the FW 200 because the thermostat is turned off and I didnt have the wires connected either but I haven’t measured for the zero volts either.
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