Electrical Wiring in the Home/Thermostat



   . I bought this honeywell thermostat that came with two wires. When I took off the old thermostat, I added the other two wires to new one because the old one had four. Anyway, I wasn't expecting 6 wires... there are three black and 3 white wires. I tried hooking it up and it was bypassing the thermostat and just running continslly until I unhooked it. Thanks so much!


The thermostat you have is a "single pole" (2 wire) thermostat. You need a "2 pole" (4 wire) thermostat readily available at HD or Lowes. It will have two red wires and two black wirres.

1 pair of the 3 pairs of black and white wires in the box goes to the heater. The other two pairs of black and white wires are the power that come into and go out of the box again to another thermostat some where in the house. In other words the two cables that come into the top of the box are most likely the power that comes into and goes out of the box and the cable on the bottom of the box goes to the heater.

The way its wired in the picture is most likely correct. The cable in the bottom of the box is going to the heater. If you have a voltage tester you can confirm by turning the power on and testing the wires that are currently twisted together. Put one prod of the tester on the two white wires and one prod on the two black wires. You should get 240 volts or there abouts. Assuming you do you will connect the two black wires on your new 2 pole thermostat to these wires. Connect one black wire to the two twisted white wires and one black to the two twisted black wires. It does not matter which black wire on the the thermostat goes to which pair of black or white. Next connect the two red wires on the thermostat to the two remaining wires of the cable that goes to the heater and your done. Again it does not matter which red wire on the thermostat goes to either the black or the white. Turn the power back on and test before putting the thermostat away. You should be good to go.

If you have no tester I am quite certain the way the wires are in the picture is correct because of how the cables come into the box. Its easy for the guys who wired the place to remember that the cable on the bottom of the box goes to the heater that way they know the two cables on the top of the box are "power in" and "power out". Again I am confident the picture is correct and if its not the worst that can happen is it won't work or you might trip the breaker but you'll be fine.


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Electrical Wiring in the Home

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Licensed Master Electrician (32 years) 6165B Contractor in Closter New Jersey with 40 years total experience in Residential - Commercial - Industrial work. Emergency Service - General trouble shooting and repair work - ONAN & GENERAC generator installation - Paddle fans - Kitchen & Bath exhaust fans - AC lines - Smoke detectors - Telephone lines - Cable TV lines - Computer network cabling - Exterior lighting - Recessed lighting - Security lighting - (200 - 150 - 100 amp service up grades) - Electric Heat - New circuits - New appliance hook ups - and more ! FREE ESTIMATES 201-358-1552 Fully Insured


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"The Frank Williams School of Electrical Construction". My dear old boss is 100 ! and still going God Bless him. I started working for "Tenafly Electric" right out of high school at 19. He was tough but I learned more working for him in 8 and half years than most guys. We did mostly industrial work while doing some commercial and residential so I was fortunate to be exposed to all 3 areas of electrical construction. The guys I worked with were all good guys and I stay in touch with some of them still. Most of us went into our own buisness's which says something about the caliber of the guys I worked with. We had some interesting clients : Wella Corp. of shampoo fame, Farah Fawcett etc, I didn't buy shampoo for 10 years. It was a great place to work. Pan Am the former airline just before they went under, another great place to work, nice clean environment. C&C Metals, the largest button manufacturer in the US at that time, a not so clean environment but a very interesting place to work, lots of machine's cranking out buttons of all kinds but you had to be on your toes, it was a potentially dangerous place to be . All kinds of action going on around you.

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