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condoowner 09-10-2012 06:46 PM

Replacing old white rodgers mercury thermostat with digital
4 Attachment(s)
Hey there!

I's like to know how to replace an old white-rodgers mercury thermostat (Model 1E30W609) by a simple digital thermostat? The current mercury thermostat controls a natural gas fireplace. Im not sure which wire to connect to the new thermostat. Plain simple, why is there 4 wires ? A black, red, green & yellow...

If I buy a replacement thermostat, I should look for a 4 wire right? Anything special I should know??

See pics! Thanks!!

White-Rodgers 09-11-2012 11:40 AM

Thank you for your interest with Emerson White Rodgers. My Name is Joselito Laxamana from technical department. You need first to tag the old terminal where is it connected like for example the Red to R terminal. For the new thermostat you can use and 4- wire thermostat then cross over the wires from the new one. For further assistance contact us at 18002842925.

JoeD 09-11-2012 12:05 PM

Looks to me like like you only have two wires really. The green and yellow are twisted together as one and the red and black are twisted together as the other.

condoowner 09-11-2012 12:54 PM

I have called the phone number as given above and talked to a tech rep who recommended the 1F78-144 as a replacement option. I amnot sure however he understood the configuration well and of course did not see the pictures I posted above..

In the end, I am not sure what are those 4 wires do....? Can anobody explain how this works? And perhaps I'll be able to find a replacement model..

kok328 09-11-2012 03:53 PM

Really can't help without more information as to where these wires connect on the opposite end.
Looks like they ran 4 wires and twisted them together to make a set of two wires (possible redundancy).
The thermostat is nothing more than an on/off switch in this setup.

JoeD 09-12-2012 08:30 AM

You really only have two wires. The wires are twisted together to make four wires into two wires.
It simple. Short them together the furnace comes on. Open them up and the furnace goes off.

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