I have an old thermostat with only 2 wires connected to my Weil-McLain CGA Series 2 boiler.
I would like to replace it with a Nest thermostat.
I need to add a C-Wire in order for it to work. Luckily, the cable coming from my thermostat already has a 3rd wire that I can use. I just need to find where to connect the C wire on the boiler side.
In attached picture, blue pen drawing shows existing wirings.
The Low Water Cut Off has 4 wires, and one is already connected to the C Common terminal.
Can I just connect my thermostat’s C wire to the same terminal? (Green pen in drawing)
Thanks!
Aquastat is I believe Honeywell L4006E1067.
Low Water Cut Off is GuardDog LB-24E.
Orange and blue nuts connectors in picture connect all the above limits + thermostat in series to the thermostat connector on boiler.
All other limits and external devices are mounted per manual diagram.
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