# NEC rules on heated floors



## Dennis Alwon (May 9, 2009)

Sparkycoog said:


> Hi there,
> I can't for the life of me figure out where heated floor rules are in the 2011 NEC. The only mention I've seen are that they should be GFCI protected, but I need to know the rules regarding distance of the elements from each other, how many watts/foot are allowed, etc. Thanks.


You need to talk to the manufactures. The mats are pre-done but the wires can be as close as 3" but generally 4-6 inches.


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## Sparkycoog (Jun 25, 2013)

Dennis Alwon said:


> You need to talk to the manufactures. The mats are pre-done but the wires can be as close as 3" but generally 4-6 inches.


That's what we have done in the past which in this part of the country was 3 times in the entire history of the company! This is more of an academic question in case it were to pop up on a test...:whistling2:


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## Dennis Alwon (May 9, 2009)

Sparkycoog said:


> That's what we have done in the past which in this part of the country was 3 times in the entire history of the company! This is more of an academic question in case it were to pop up on a test...:whistling2:


I don't believe that would be on a test as it is not really an NEC issue but a manufacturers requirements.


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## HARRY304E (Sep 15, 2010)

Sparkycoog said:


> Hi there,
> I can't for the life of me figure out where heated floor rules are in the 2011 NEC. The only mention I've seen are that they should be GFCI protected, but I need to know the rules regarding distance of the elements from each other, how many watts/foot are allowed, etc. Thanks.


You want to look at this section of the code but I'm not sure the answer to your test question .

424.99 Installation Under Floor Covering.
(A) Identification. Heating panels or heating panel sets for installation under floor covering shall be identified as suitable for installation under floor covering.
(B) Maximum Heated Area. Heating panels or panel sets installed under floor covering shall not exceed 160 watts/m2 (15 watts/ft2) of heated area.
(C) Installation. Listed heating panels or panel sets, if installed under floor covering, shall be installed on floor surfaces that are smooth and flat in accordance with the manufacturer’s instructions and shall also comply with 424.99(C)(1) through (C)(5).
(1) Expansion Joints. Heating panels or heating panel sets shall not be installed where they bridge expansion joints unless protected from expansion and contraction.
(2) Connection to Conductors. Heating panels and heating panel sets shall be connected to branch-circuit and supply wiring by wiring methods recognized in Chapter 3.
(3) Anchoring. Heating panels and heating panel sets shall be firmly anchored to the floor using an adhesive or anchoring system identified for this use.
(4) Coverings. After heating panels or heating panel sets are installed and inspected, they shall be permitted to be covered by a floor covering that has been identified by the manufacturer as being suitable for the installation. The covering shall be secured to the heating panel or heating panel sets with release-type adhesives or by means identified for this use.
(5) Fault Protection. A device to open all ungrounded conductors supplying the heating panels or heating panel sets, provided by the manufacturer, shall function when a low- or high-resistance line-to-line, line-to-grounded conductor, or line-to-ground fault occurs, such as the result of a penetration of the element or element assembly.
Informational Note:  An integral grounding shield may be required to provide this protection.


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## Sparkycoog (Jun 25, 2013)

Dennis Alwon said:


> I don't believe that would be on a test as it is not really an NEC issue but a manufacturers requirements.


I didn't think so either but it popped up on a certain test I was taking. I don't remember the exact question but it was on the topic. I appreciate your response however.


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## Sparkycoog (Jun 25, 2013)

HARRY304E said:


> You want to look at this section of the code but I'm not sure the answer to your test question .
> 
> 424.99 Installation Under Floor Covering.
> (A) Identification. Heating panels or heating panel sets for installation under floor covering shall be identified as suitable for installation under floor covering.
> ...


I think that's what I need! It must have been panels.


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