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sob 10-19-2009 04:24 PM

Thermostat wiring question
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I'm trying to install programmable thermostats for my baseboard electric heaters. The new thermostat only has 2 wires, whereas the old ones have 4. I plan to wire up the new one by simply combining the 2 reds and the 2 blacks off of the old thermostat into the new one.

That is;
1. Cut all 4 wires off the old thermostat
2. Combine the 2 red and attach to wire 1 on the new thermostat
3. Combine the 2 black and attach to wire 2 on the new thermostat.

Is this the right approach?

beenthere 10-19-2009 05:32 PM

NEC requires line voltage thermostats to be a double pole.
Apparently your new ones are not double pole. So they do not meet code.
Your home owners insurance may not cover you, if you use these thermostats.
may want to contact them before installing those stats.

sob 10-19-2009 06:55 PM

I'm in Canada and I'm pretty sure single pole is allowed.

But w.r.t. wiring, I'm not sure how to proceed. If I do what I described in my first post (combine the reds and the blacks on the old thermostat) I will be mixing reds and blacks coming out of the wall.

Or, should I make my two connections by combining all the reds out of the wall and all the blacks out of the wall and connecting the new thermostat to them?

If you can't tell from the picture;
There are 2 wires coming into the box (containing a red/black each) and 1 wire on the bottom left (containing red/black too).

beenthere 10-19-2009 07:11 PM

Your current stat is a 2 pole.
They cost slightly more then single pole ones.
Most contractors don't install a more expensive thermostat then they have to for electric baseboard.

I think you may be in error on your code allowing single pole.
Canada has stricter codes the USA.

Post pics of your new stat

sob 10-19-2009 07:25 PM

This is the new unit.

There are 2 black wire sticking out if the back...

The reason I want to install this is because I have 14 thermostats in the house and would like to program them to save some energy.


beenthere 10-19-2009 07:51 PM

I understand why you want to use a programable thermostat.

I see its half off. Probably because its not an approved thermostat.

PS: That site has wiring instructions for your set up.
I won't give instructions for things i believe are against code.

Read some of those reviews. people have had trouble getting the thermostat to turn the heat off.

sob 10-19-2009 08:30 PM

1 Attachment(s)
It's CSA approved.

They are rated for 3000W@240 or 1500W@120

sktn77a 10-20-2009 01:55 PM

I see 4 wires coming from the thermostat and what looks like 6 wires coming out of the box. I also see red wires connected to black wires and vice versa. Looks like some strange wiring I'd want a pro to sort out.

sob 10-20-2009 09:01 PM

I had friend (who is an electrician) come and look at it and this is how you do it.

- Remove the old thermostat
- Tie all the reds together. This connects the source power to the thermostat and the exiting wire. With the 3 black wires remaining;
- Two are already paired. These two complete the connections for the source power and the exiting line. Leave them together.
- Place the thermostat between the paired black and the single black.
- When the thermostat is on, it closes the connection and power runs through the heater.

Also, my friend told me he doesn't see many double pole thermostats being installed these days. It's mostly all single pole.

beenthere 10-21-2009 04:52 AM

I don't see many furnaces or boilers being sized properly these days either.
So does that make it right.

Tell us about it, when your room is 90 because those contacts burnt closed.

sob 10-21-2009 07:02 AM

Yeah sure, I'll do that...

You know... Canada is a whole different country, we sometimes do things differently.

Thanks for all you *help*.

beenthere 10-21-2009 10:31 AM


Originally Posted by sob (Post 343555)
Yeah sure, I'll do that...

You know... Canada is a whole different country, we sometimes do things differently.

Thanks for all you *help*.

You know. Electric works the same, in Canada, as it does in the USA.

Your *welcome*.

PS: Those same wiring instructions are on the site you posted a link to.

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