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Line Voltage Radiant Ceiling heat - Unclear on what electrician told me.

Line Voltage Radiant Ceiling heat - Unclear on what electrician told me.

Old 02-08-14, 10:45 AM
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Exclamation Line Voltage Radiant Ceiling heat - Unclear on what electrician told me.

I have a living room, 14 x 20 and a kitchen area 8 x 8, tied together for ceiling heat. All was fine for years but then thermostats began burning up. I recently brought in a electrician who said the wires at the thermostat box are pulling 22 amps but the wire is rated for 20 amps. He says he will need to pull a #10 wire and add a 6 x 6" box with some sort of converter or transformer) to save future thermostats and to be safe.

My questions. Why, after 25 years, is it burning thermostats up? (He checked and says there are no breaks in the heating wire).

Do I really need this 6 x 6 box/converter set up? (He said the thermostat would kick on the converter/ or transformer and then the converter or transformer would drive the line voltage radiant heat.) (He also said it would cost $400 to $500!

Could I do better with a line voltage thermostat rated at 22 amps?

I AM a newby so appreciate any constructive replies.
Old 02-08-14, 11:08 AM
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Unfortunately you have an unsafe condition there. On a #12 wiring circuit there should only be a continuous load of 16 amps. Basically that is 80% of the maximum circuit ampacity since resistive heating, which is considered a continuous load, is in use.

I don't know of an electric thermostat available today that can handle 22 amps. Most are rated for 15-16 amps (3800w) max. and you might find one for 5000w but that is only 21 amps max.

Your electrician wants to install a switching contactor which is the only correct way to handle that much current switching safely. In the long run, that circuit should really be split in to two circuits.
Old 02-08-14, 06:42 PM
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Did you make changes or additions to the circuit?

Perhaps one of the heating elements degenerated in a fashion that it now draws much more current than it is supposed to.
Old 02-09-14, 06:00 PM
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Thanks to AllenJ & PJmax

Thanks to both of you! It is greatly appreciated.

AllenJ - My electrician said it looked like the kitchen area had been tied into the living room area. (Not on my watch). It did work fine for years and then started burning up T-stats. (About 1 every 3 or 4 years, I guess)

PJmax - Yep! That is what he called it. It confused me because I had not heard of it before and I thought the phone signal had garbled at that point.

Since the cost is going to be a minimum $400, I will ask him about splitting the line. Heck! I might as well give it to him instead of drinking it up, which also keeps me warm.

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