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Gas hot water boiler

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I recently replaced my oil fired hot water boiler with a gas fired hot water boiler. My problem is that I have 2  line voltage thermostats and my new boiler is set up for liw voltage (24 volts). To replace the thermostats will involve breaking open walls and ceilings, I’d rather not do that. Is there a way I can still use my live voltage (110 volts) thermostats with this new system? Any help would be greatly appreciated. Thanks

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  • Ironman
    Ironman Member Posts: 7,379
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    Wireless thermostats.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,634
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    Disconnect your line voltage stat and take it off the wall. Splice a short piece of low voltage cable to the line voltage cable and reconnect it to the thermostat (or better yet to a new low voltage stat) and mount the thermostat on the wall. Find the line voltage cable at the boiler and splice some low voltage cable to it and connect it to the boiler where the low voltage thermostat would connect.

    MAKE ABSOLUTLY SURE YOU HAVE THE RIGHT CABLE AND THAT NO OTHER LINE VOLTAGE OR CONTROLS ARE WIRED TO IT.

    you should ring out the cable with an ohm meter to make sure you have the right cable. if in doubt call an electrician
  • pecmsg
    pecmsg Member Posts: 4,895
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    There are many ways of getting a new 18/8 cable pulled with little if any damage!

  • hot_rod
    hot_rod Member Posts: 22,268
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    Many of the new thermostats need a common wire. So you may need  3 conductors
    If possible pull some new 24v wire
    maybe some 5 conductor for AC option down the road
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Jamie Hall
    Jamie Hall Member Posts: 23,454
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    Or leave the line voltage thermostats and use them to control a relay or relays in the basement. They control the coil, and the 24 VAC boiler circuit through the normally open contacts.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England