Electrical Wiring in the Home/Electric Heater Thermostat


QUESTION: Hi Robert,
I moved a wall mounted thermostat thermostat operating a 1500 watt 240V electric wall heater. I got it working, but there seems to be no place for the ground to go in the thermostat. I just duplicated the wiring I found which was white to Black T1 and Black to Black  L1.

There are two remaining Red wires, T2 and L2. But nothing marked for the ground.  The ground was just capped with a wire nut in the thermostat when I found it, and this just seems wrong to me.

The thermostat seems to be a Honeywell YCT410B1000 Manual 4 Wire Baseboard/Line Volt Thermostat. When I looked for wiring diagrams it just didn't show a ground wire.

I have all three grounds tied together in the heater itself. What to do with the ground in the thermostat? Thanks

220v line voltage thermostat
220v line voltage ther  
ANSWER: Hello stephen,
Hi my name is Robert and ill be helping you today,before you go any further you have some wiring issues it appears that you have the unit miswired I will contact you shortly and correct the wiring for you however t1 stands for thermostat and l1 stands for leg Or line

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QUESTION: Love to know how it's wrong. Thanks.

ANSWER: Hello stephan, I'm not sure what happened however have my message is missing and only the picture i sent went through...Anyway the way you have it wired right now would leave only half the heating elements working... L1 &L2 stand for Line1 and Line2 and or Leg1 & Leg2 Now the T1 and T2 Stand for Thermostat 1 and T2 Thermostat 2 so what you need to do is simply take your incoming power which should be a Black and Red and splice each 1 to a leg of the thermostat so it would be your L1 to One of your hot legs and L2 to the other hot leg than your simply going to take each one of your Thermostat legs and splice them to the wires coming off the heater it  doesn't matter which one just put T1 to one leg of the heater and T2 to the other leg of the heater as far as the ground there SHOULD be a green screw and you can simply add a tail to all the grounds and put the tail to the green screw.I hope this helps and please contact me for ANY concerns or for further clarification.

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QUESTION: Hi Robert,
Perhaps my description was not clear. The power 10-3 wire goes directly to the heater. I then have a 12-2 wire, which is tied in at the heater,  going to the thermostat from the heater. So only a black, White and ground wire are present at the thermostat. There is no green ground nut present on the thermostat.
Thanks, Stephan

Ok Stephan,
That's a horse of a different color so lets get to it and wire this puppy up that being said lets see if i understand you correctly you have a 4 wire line voltage which has 2 red wires & 2 black wires 1 set says L1 and T1 than the other set says L2 and T2 just like the picture I posted in which is mounted on your wall separate from the heater which has A 10/2 cable going to the heater than when you open the heater you have the 10/2, along with a 10/3 which is your power from your panel than finally your 2 wires from the heater itself.Is this the situation that you have?
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Electrical Wiring in the Home

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Robert Tomasulo


I am here to answer ALL your questions regarding anything to do with home wiring such as Switches, Receptacles,Lighting, Main Distribution Panels, HVAC, Thermostats, etc; if it has a wire and in your home I CAN ANSWER IT. Whether its as simple as "why do my lights flicker?" Or as complex as I would like to rewire my house im here to help, in addition i can offer advice on remodeling a kitchen or lighting up you back yard as well as offering troubleshooting on appliances.


I have over 17 years in the electrical industry including Residential, Commercial & Industrial, Im also a certified HVAC technician as well as a certified fiber obtic technician.I am currently employed by the New York City Transit Authority as the Senior Electrical Maintainer and serve as the Relief Foreman for the electrical maintenance division for the past 12 years.I also hold many certifications, licenses and certificates in my field

FOA Member(Fiber Optic Association) UTU (United Transportation Union) IBEW (International Brotherhood of Electrical Workers) HVAC/TALK (Heating & Air conditioning troubleshooting group)

5 years of technical school after high school in electrical installation and design sponsored by Local 3 (IBEW) As well as over 17 years of hands on in the field training and education, and till this day im still learning, Not a day goes by that i don't learn something and if i feel i didn't i will open up a book to insure I DO!

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