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lee12 · Feb 8, 2011, 06:44 PM

Would a 240v kickspace 1500W electric heater in a bathroom require it's own circuit? Or could it be part of a circuit that includes other baseboard heaters?

ma0641 · Feb 8, 2011, 07:21 PM

Depends on the wire size and breaker capacity. What are they? How many heaters are on the other circuit? You will need to determine the load before making a decision.

lee12 · Feb 8, 2011, 07:39 PM

12 gauge wire, 20 amp breaker. I would include a second 1500W heater for the adjacent room if allowed. That shouldn't put me in any danger of overloading the circuit, I simply don't know what all the codes specify. For some reason I thought bathroom heaters might need to be on designated circuits. Wanted to check first before wiring anything. Thanks.

Missouri Bound · Feb 9, 2011, 09:30 AM

You will need to put the heater on it's own, dedicated circuit. Does it have a built in thermostat? How will it be controlled? A 240v 1500 watt heater can go on a dbl. pole 15 amp breaker, with 14 ga. Wire. If you plan to add heater, you will need to increase the circuit to 20 amp and use 12 ga. Wire.

lee12 · Feb 9, 2011, 11:57 AM

Thanks. The heater will have a wall mount thermostat.

Just to be clear - you are saying that NEC specifies heaters in bathrooms cannot be on the same circuit as heaters for other rooms, correct? Just want to be sure. The last electrician I had out here said that wasn't the case. I wanted to double-check it though.

tkrussell · Feb 9, 2011, 12:04 PM

Technically, Per Code, a heating unit branch circuit wiring and circuit breaker is to be considered as a continuous load, See Section 424.3(B) of the 2008 NEC, and therefore, the circuit wiring and breaker shall be rated 125% of the load.

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INCORRECT ANSWER PROVIDED, AND REMOVED BY ORIGINAL POSTER, ME.

Missouri Bound · Feb 9, 2011, 12:25 PM

TK, it's a 240v heater... 6.25 amps per leg... At least it better be a 240v heater.

lee12 · Feb 9, 2011, 12:49 PM

Little confused by your calculation tkrussell, would you mind elaborating a little?

You say 1500W x 1.25 = 15.625. I've got to be missing something here. I thought the way this was done was 1500W/240V = 6.25 amp. To increase that by 25% would be 7.8125 amps. Maybe we're talking about different things here though...

lee12 · Feb 9, 2011, 12:55 PM

Yes - 240V is correct. I understand the confusion now with the calculation.

tkrussell · Feb 9, 2011, 03:09 PM

Oops sorry, thought it was 120 volts, clearly it is 240, my mistake.

Plus I screwed up the formula.

Having a really, really bad day, I won't bore with the details, but does involve personal injury, should have stayed in bed.

Sorry Lee, listen to Missouri.

lee12 · Feb 9, 2011, 04:45 PM

No problem, happens to the best of us - hope things start looking better for you soon.

Missouri Bound · Feb 9, 2011, 07:20 PM

Not sure if you ever got your answer. Yes the heater can be on a circuit with other heaters, providing all the electrical requirements are met. If you already have a 240 amp heater circuit in place, take a load reading before you plan to add anything to it. If it was my installation, I would run a new circuit for this heater. But you can't add it to just any 240v circuit, such as a range or water heater. And if you already have some heater(s) in place, it's likely it was fused (protected) and wired with a circuit that would prevent the addition of this new heater.

hkstroud · Feb 9, 2011, 07:51 PM

Where do you plan on tapping into the existing circuit? I'm sure you realize this but just in case, you must tap into the line side of the existing thermostat. Otherwise the bath heater will only function when other heater are operating.

lee12 · Feb 10, 2011, 05:37 AM

Thanks for all the input here!

Should probably have mentioned this before but this is part of an addition with a handful of new 240v heating circuits and 120v general lighting/receptacle circuits. So I won't be tapping into anything existing (other than the panel). Just trying to plan out my wire runs at this point. Had originally intended to have this heater on it's own circuit because for some reason I thought that's what was required. When I had an electrician in to talk about adding a sub-panel he mentioned that a dedicated circuit wasn't necessary. Was just trying to find out what was correct. If I decide to have 2 heaters on this circuit they would each drop down from a junction box in the attic so I should be able to easily separate the thermostats.

Thanks again for all the help.