I have 3 baseboard heaters to wire. One going to the den and 1 in each bedroom. The bedrooms are back to back and the den is about 8 feet away. Can I run these all off one 220 breaker? Would I need to use 12/2, 10/2 or 8/2 wire to run them? Would it be best to make a junction box to split them all out of or can I wire them in a series, 1 after another? Or is this even possible, do I need a separate circuit for each one. Also how much heat will a baseboard heater put out. Will 1 heat a 10x10x10 bedroom with decent insulation? The problem is that the heater also does not have any instructions on wiring it. If I am running a 10/2 wire to it how do I hook it up? I know this is a long post, I appreciate all you help.

Before any of the various questions can be answered, the size wattage of each baseboard heater is needed.

Once this is know, then the size circuit(s) can be determined.

Generally speaking, to size electric heat for a given space, use 9 watts per square foot in the exterior walls are 6 inch insulated, and 11 w/sq.ft. for 4 inch insulated walls.