Electronic Thermostate NOT WORKING! My mercury thermostat has a blue wire connected to the upper left, white wire to the bottom left and a red wire to the bottom right. When I replaced it with my electronic one, I supposed that that the Red wire went to R, White went to W and I left B alone. My furnace has a red and white wire connected to it. The problem? NOTHING is labeled! So, I am just presuming the wiring (done in 1962) used the color code to match the W and R. When I set the electronic thermostat to 68 degrees, it kept my house at 75 degrees and kept my gas hot water pipes going (for 2 days), even though the thermostat screen did not have "heat on" showing. When I set the room temp to 80degrees, the thermostat kicked on and showed "heat on" to raise the room temp. This is the second time I have tried to change my mercury to electronic and the same thing: it heats up but will not shut off to get my living room to 68 degrees.