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Recently bought a home with a Weil-McLain ultra 105 series 2 boiler. I’m looking at relocating the thermostat and putting in a smart thermostat. My questions is I’ve never seen one with a low voltage strip and was wondering where I would put the C wire? I’m gonna attach the schematics.enter image description hereCurrently red wire for thermostat is in number 5 and white is in 6, with factory jumpers going from 6 to 8 and one from 6 to 7 also.enter image description hereThank you and sorry if it’s been asked before.

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    Good question, but you may need to call Weil-McLain for this one -- their control supplement for your boiler is disturbingly silent on the topic of C-wiire hookups, AFAICT Commented May 15, 2022 at 0:09

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Got it solved by accident lol. When I went to turn off the ac at the breaker totally forgot about the air handler in the attic. Blue wire and white wire for the ac was just shoved in the wall not hooked to anything. When I pulled them out they touched and it sparked. So ran down stairs to shut that breaker off(rookie mistake). Ended up being blue wire was hooked up to be a c wire from previous owner and just shoved in the wall. Traced it back to the air handler.

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  • Glad you were able to track down a suitable C-wire! (Doubly so because most thermostats pair C with Rc when set up for a two-transformer system like yours) Commented May 15, 2022 at 2:10

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