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Temp Control with Shutoff Wiring Question

kredmore Member Posts: 53
edited January 2018 in THE MAIN WALL
See attached diagram. I have an old Hot Water Boiler system with two zones working fine. Installed Hydrostat (to replace original aquastat), and again, all is working fine. However, I'm trying to figure out how to provide 120v power to the Hydrostat within existing setup to leverage the shutoff (and not have a separate 120v line with shutoff - as I have it now temporarily).

I keep reviewing the diagram to try to find a way, but can't figure it out. Thinking a simple diagram here might be easy for someone with way more experience.

Thanks, Keith


  • STEVEusaPA
    STEVEusaPA Member Posts: 6,505
    edited January 2018
    The same place you brought in your 120v for the old aquastat.
    Should go from your breaker panel to a thermal switch to a shut off switch at the boiler to L1 on the aquastat. For your zone controls, you can either bring in 120v separate as it's own circuit or from main shut off at the boiler as long as the zone panel, transformer and circulators aren't drawing too much power. You'll need low voltage wiring from x-x on zone control to t-t on the Hydrostat.
    Note, if your shut off at the boiler doesn't shut everything off, you should note that on the zone panel and transformer to help whoever will be working on it to not get zapped, or damage some equipment.

    There was an error rendering this rich post.

  • kredmore
    kredmore Member Posts: 53
    Thanks for the reply. I should have stated that the old aquastat was only a temp switch with low voltage going through it. No 120v input.

    The current shutoff in place, stops thermostat demand into the new Hydrostat (or into gas valve/aquastat in the old setup), so would another option be have the Hydrostat on a separate 120v line, since no demand is going in/out upon current shutdown?

    I still think there is a way to get the Hydrostat in the diagram for complete shut-off. Will continue looking at it.....

    I also had a zone damper motor die on our 2nd floor furnace (AC in summer) yesterday....HVAC work is fun...:)
  • kredmore
    kredmore Member Posts: 53
    I was able to re-arrange for one shut-off in this order - Power to Shutoff to Hydrostat/existing setup (zone control, pumps, etc.).

    Simple really - just had to work through the existing electrical setup to get to that point.