rewiring 120v to 240v

[bill2]

 d*I screwed up. I am about halfway thru my cabin build and I discovered in the 3 upstairs rooms where I want to install baseboard heaters I wired them for 120v and they should be 240v. I haven't finished some of the walls but to rewire I will have to fish new wire and/or take out existing but unfinished drywall (no big deal) but in one location I have tongue and groove horizontal paneling already up. Can I just run a second 120v wire and connect them together to have a 240 outlet? Any suggestions would be appreciated. Thanks

[bayview]

   Only if you connect the additional 120 volt from the second or other leg coming from the breaker box.   Coming off the same 120 volt leg would be running the 120 volt in parallel.   That won't work . . .

   Use the two  "Hots" for the 240 volts.   Connect the two neutrals together, and the two grounds together. . .

/.

[ChuckinVa]

If you used a 12/2 with ground romex, that is all you need to wire a 240 volt baseboard heater. The white wire is used as a hot just like the black and the bare is a ground. There is no neutral. if you prefer, you can buy 120 volt baseboard heaters but there is no need to do that. Here are instructions [http://www.marleymep.com/en/multimedia-library/pdf/qmark-pdf/products/base-board-heaters/2500-series/2500wiring.pdf]

[glenn kangiser]

The neutral can be marked as another hot with tape.

[cmsilvay]

As long as the run is a home run to the box and nothing else is on the circut and it is 12/2 you are good to go. Just like everyone said thier is no neutral on wiring for these heaters. Just wired one in out new addition as an after thought i stole a run that I had run as a xtra  circut in the bedroom that was planed to be on a surge protector in case we put a Tv in there

[rocking23nf]

There is more to this then just changing the neutral to hot.

You need to ensure it has a 20amp breaker.

You need to calculate the load of all devices on the circuit. If its baseboard heaters, 2 is fine, 3 is likely over the limit.

how many watts are the heaters? if they are 2000 watt heaters, you will need a circuit for each heater, and on its own 20 amp breaker.

1500Watts x 3 heaters = 4500 watts/240V = 18.75 Amp, which is too high for a 20amp circuit. The max allowable is 80%, which would be 16Amp

Also if the wire is not 12-2, you will need to rewire.