Due to the remodeling of a bathroom, I want to add a 220V, 1000W baseboard heater (no heating before because the bath has no exterior walls). I have an empty 220V 15A double pole breaker in my panel which used to feed a small tabletop stove which is no longer needed with a 12/2 (red/black) + ground cable coming out and I will use this cable to feed a junction box and from there a new cable will go to the tstat and another to the new heater. All new cables will be 12/2 (red/black) + ground. At the junction box I will connect the 3 black wires together and the 3 red together. At the tstat I will connect the tstat between the black/red and at the heater I will connect black to black and red to red. Anything wrong with this installation? Thank you all

 

Do not wire it this way.

You are putting your tstat in a parallel condition and thereby creating a direct short with both legs of your 240 volt ckt. I don't know how you got 12-2 /wg with your conductors red and black, usually 12-2 w/g nm is a white, black, and bare (ground) sheathed together. What you could have is 12-3 w/g and the white was snipped back.

At any rate, you need 2 #12 conductors and a ground to do this. If you are going to use your current wire and are sure it is acceptable, wire your ckt like this:

At the j-box, wire the feed in black to the heater supply black. Take the feed in red and wire to the tstat supply red. Then take the tstat supply black and wire to the heater supply red. This will put the tstat in a series condition and it will act as a switch. Take your ground wire and connect it straight through the ckt making sure the j-box, tstat box, and heater unit are all grounded.

A good question is why not just put a tstat on the heater unit and eliminate some of this...?

 

Thank you for the good input. My cable it is 2 #12 and I know this due to the existing installation from the portable stove. It is easier to use a tstat on the heater but this will be a bath for my teenage girls and they prefer to have a wall tstat instead of one on the heater. Thanks so much

 

kolias,

I think you are confused about 240 volt wiring. With 240 volt wiring, there are two hot wires.

In your case, your wiring needs to go from the junction box to the thermostat to the heater. If you want to go from the junction box to the thermostat back to the junction box and then to the heater, then you will need two wires (plus grounds) for each of those runs. In other words, you will need four wires (plus a ground) between the junction box and the thermostat.

 

Indeed this 240 volt ckt has 2 hots-however he only needs to break one leg across the tstat to properly control it. Wiring his ckt the way I described accomplishes this.

Likewise, to install the tstat locally on the unit itself would require wiring it the same way-it would just take less wire and eliminate the wall tstat location.

 

Yes, you only need to break one wire. However, I strongly recommend that both wires be broken. It makes the wiring much easier to understand and follow and is much safer.

 

racraft,

There is no way I agree with your last post but I can agree to disagree about different views and approaches to different wiring schemes.

The point is kolias has some good information to work with and if he at least understands not to introduce both legs of his 240 volt circuit by way of his tstat as he originally posted, I'll die a happy man...

 

I'm not sure how you can't agree with my position.

I have seen and heard of too many people who turn off a light or a receptacle by a switch and then go work on it, only to be shocked because they don't understand the concept of a switch loop. Switching one leg of a 240 volt circuit with a thermostat is the same thing. Someone somewhere is going to do this (perhaps no this poster, but someone) and work on the circuit, only to get zapped by the unswitched hot leg.

As for the wiring, this forum has shown over and over again that direct wiring is much easier for do-it-yourselfers to understand. Whenever switch loops, or other non-direct wiring solutions are involved, people get confused. Wiring a 240 volt circuit and running a switch loop from a junction box on only one leg of a circuit would surely be confusing to many who post here asking for help.

Yes, you did post a solution that works. However, it is not the easiest to understand and it is not a solution that I would implement for myself, let alone ever tell anyone else to implement.

 

Why not use this type of heater with buil-in thermostat and off/on switch? Takes up less room than a baseboard heater.


http://www.cadetco.com/support/specsheet/1002.pdf


Here's a heat calculator to make you size the heater correctly.


http://www.cadetco.com/heater_selection.php