I've roughed in wiring to install 2 baseboard heaters in a room in my basement.I want to make sure that I got it right.I ran 12/2 wire from the panel to the wall thermostat box,then a separate 12/2 line out to each heater location.I want to use one 1000w heater and one 1500w heater and put them on 20 amp breaker.

Sounds perfect. I really have nothing to add.

Does the thermostat switch the full load, or just control the coil of a relay? The way I read your question, one 12-2 is feeding 2500 watts. Of course, that is fine if it is 208 or 240 volts.

Yes they are 240 v heaters and I will be using a double pole thermostat.

OK, I didn't want to chance tkrussel missed a detail. Otherwise, I would expect his answer to be correct. Sometimes people give wrong answers because they didn't see the question quite right.

Thanks for the backup Labman,just sometimes I take things as understood, and I realized I should not do that.

I've been trying to install a new baseboard radiant heater, just as dennis6 described, but the unit will not heat up. I finally bypassed the thermostat and hot wired the unit (in order to determine if the thermostat was the problem) but still no heat, even though the wires at the unit test hot.

I have a 12/2 wire running from the panel directly to the baseboard unit. Ground is attached to grounding screwin the heating unit, and the (hot) white & black wires (coming from a twin 20 amp breaker) are attached to the two wires on the 240 Vac heating unit. Still no heat.

What am I missing here?

Is there an independent test for determining whether the heating unit is defective? I bought two of them, and neither works under the scenario I've described.

Any thoughts appreciated.

Bob

Use an OHM meter to see if there is impedance in the circuit. That will tell you if the heater is good. Also check to make sure you have voltage going to the heater and to the right wires on the heater.

Thanks for the suggestions. The ohm meter tells me the heater (actually two separate units) is good, and I've also verified that power is at the unit. The meter shows 120 Vac on each of the two heater wires when I contact them (separately) with the ground.

As an addendum, the heat unit has two wires, both covered with some sort of fabric-looking sleeve, probably to protect from high temp. Since the unit is 240 Vac, the wires going to the unit are a ground and two hots, so it should not matter which hot is attached to which heater wire.

Correct it will not matter which hot legs are attached to what element wire. Is there a overload built in the heater. Some heaters have them and there can have a red button on top to reset them. Take a good look inside the heater.

Check to be sure you are using a true 240 volt 2 pole breaker. You may be using a tandem breaker, has two small handles in one space of a single pole breaker.

If this type of breaker is used on one "phase" or hot leg of a panel, you will see 120 volt to ground from each hot wire. You don't say what happens when tested across both hot wires. You should see 240 volts.

Then there is the true two pole breaker, half size, again you can install on one leg getig the same results.

Get back with the part numner of the breaker and I should be able to tell what you have.

Thanks to you and others who thought about and suggested solutions to my problem. Tk - you were spot on! I was using a tandem breaker with both circuits on the same phase/buss bar. When I took one leg of the wire off that breaker and put it into a separate 20 amp breaker on another phase, the heater lit up like a Christmas tree (metaphorically speaking).

Thank you