# Replacing old white rodgers mercury thermostat with digital



## condoowner (Sep 10, 2012)

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!!


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## White-Rodgers (Sep 11, 2012)

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.


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## JoeD (Sep 11, 2012)

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.


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## condoowner (Sep 11, 2012)

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..


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## kok328 (Sep 11, 2012)

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.


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## JoeD (Sep 12, 2012)

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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