I purchased five wall heaters for hook-up in series in my basement. They are 240 volt and I'm setting them to 900 watts - which pull about 4.6 volts each. I've placed a 30amp double circuit breaker in my panel. The heater instructions tell me to run power first to the thermostat, then to heater. I ran orange #10 four-wire to the first heater. The thermostat has two wires, the heater three (red, black, greeen). Do I pigtail black to black and red to red on the thermostat and not use the white and ground wires; then on heater wire black to black, red to red and pigtail green, white and copper ground wires together?

Hi - you've said a few things that don't make sense... so let's go back to the basics.

What you call a 4 wire #10 - do you mean it has black, red, white and bare copper? I assume yes.

When you say you have 5 heaters - are they each 900W, so 4500W in total? I'll leave it for the others to comment on whether this wire is sized correctly. By the way, you are actually connecting them in parellel (although it may seem like they are in series because you are running from one heater to the next). The voltage at each heater will be 240V, not 4.6V.

If you are running from the panel to the thermostat first, then you will need a different thermostat - look for a 240V double pole thermostat. They should only be a few dollars more than the single pole one you have, and are safer.

OK - at the thermostat, connect the incoming black to the outgoing black through one side of the thermstat. Connect the incoming red to the outgoing red through the pair of wires or terminals on the other side of the thermostat. Do not use the white wires. Pigtail the bare copper wires together and to the grounding lug on the box.

At each heater, pigtail all black wires together plus one black from the heater. Ensure you have the correct sized marrettes for the number and gauge of wires you have. Also pigtail all red wires together with one red wire from the heater. If the heater does not have a red wire, then use whatever coloured other insulated wire there is in the heater instead (including possibly a second black wire). Do not use the white wires on the wire from the thermstat or to the next heater. Pigtail the bare copper wires together and to the ground lug on the heater

I hope this makes sense to you. Ask questions if it does not.

In Canada, we have Heatex wire for heaters - it is rated for higher temperatures and only has red/ black/ bare wires in it.

Here see if this helps also, the arrows in the heater continue to the next heater.

Also, marrettes means splices or wirenuts in the US.

Is that French? I see English use that word also.

Sounds french, but I don't know the origin, Tom. I've always called them marrette... although I notice that the last box I bought at my local orange big box were labelled 'wirenuts'.
D@mn - you americans are taking over... first it was that more and more devices have philips screws instead of robertson... now you're exporting your terminology too! :) :)

You are correct that it's 4500W total for five heaters and my wire from panel has three wires plus copper ground (10-3). I also should have said 4Amps each heater not Volts. The thermostat I have is Ritetemp 6002A and says for 240V units - doesn't mention single or double pole. Instructions say Black wire goes to Line and Red to Load - no ground on thermostat - is that a problem? I'm confused about not using the white wire from panel since both white and copper wire are fastened to ground strip in panel. So the white wire is not used at all in wiring any of the five heaters? Thank you.

I googled ritetemp 6002A and didn't find anything. You want a thermostat that has 4 wires or terminals on it. The red wires are connected to the thermostat through one pair, while blacks are connected through the other pair (see TKRussell's diagram). A non-programmable 240V double pole thermostat is less than $20 at your local big box, and may be a code requirement. A single pole would work, but would leave each heater with one live line even when the thermostat is not calling for heat - so a double pole is safer.

If you have a cable with red and black wires, you do not need the white. Look back at TKRussel's diagram. The top wire is red or black. The middle wire is the opposite colour (black or red). The bottom wire is the ground (green or bare) wire. There is no white required. If you took a voltmeter and measured between white and red (or black) you would find 120V. Measure between red and black and you will find 240V. The heaters you have use 240V, so the white wire is not used and should not be connected anywhere.

White is "neutral" whereas green or bare is "ground". They are connected in the main pael to provide a common potential difference to the line cables. While neutral and ground are at the same potential, white is only used for 120V power circuits, whereas the ground is only used for safety. The only place they are allowed to be connected is that one connection you already found in the main panel.

No ground on the thermostat is normal. You should ground the box it's contained in though, and each heater too.

Thank you all for great answers!