Honeywell prestige - common wire

Old 01-02-15, 04:48 PM
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Honeywell prestige - common wire

I have a Honeywell prestige furnace with mcba54201DV10 controller. I am trying to hook up a new wifi thermostat but it only has the R and W hooked up. It has 3 wires but the green is not hooked up to thermostat nor furnace. If I understand the C or Common wire, it is just a 24V power supply. I can not find an equivalent in my furnace. Can you help me hook up Common wire?
Old 01-02-15, 06:06 PM
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Is your furnace a boiler?
Is the thermostat R and W connected to terminals labeled T and T at the furnace?
Old 01-02-15, 11:09 PM
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I can find pictures but I couldn't find one piece of useable tech info for that boiler controller.
Some well lit pics of the control board wiring may be helpful here.

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