Overview

Heating panels and heating panel sets are complete assemblies utilized for efficient, eco-friendly, and sound-

proof heating. However, installing these devices within walls requires adequate

protection against mechanical and electrical stresses. Previous editions of the NEC did not address these protection requirements, resulting in reluctance within the industry to adopt this practice. In the NEC 2023, a new subsection 424.93(C) was introduced to highlight the requirements for such installations. This modification will incentivize manufacturers to develop heating panels suitable for wall installation and establish a standard practice for installing heating panels in walls.

Applying the 2023 Code

A heating panel is a comprehensive assembly, featuring either a junction box or a length of flexible conduit for connection to a branch circuit. Conversely, a heating panel set comprises an assembly, either rigid or nonrigid, equipped with non-heating leads or a terminal junction assembly suitable for connection to a wiring system. These panels have emerged as a superior alternative to many conventional heating systems due to their quiet operation, environmentally friendly nature, space-saving design, and cost-effectiveness. However, the heating portion of the panel cannot be installed in walls without adequate protection against mechanical and electrical stresses. Furthermore, such installations have not become common practice in the industry due to the absence of a standardized list of required protections. To address this issue, a new subsection, 424.93(C), was added in NEC 2023 to describe the requirements for installing a heating panel inside a wall. These changes will enable equipment manufacturers to develop new heating panel products that can be readily installed in walls.

What’s New for the 2023 NEC?

2020 NEC

No reference to installation requirements of heating panels in wallks can be found in NEC 2020.

2023 NEC

(C) Installation of Heating Panels in Walls

Unless prohibited by 424.93(A)(2), heating panels shall be permitted to be installed in, on, or behind walls provided all of the following are met:

1. Heating panels shall be identified as suitable for installation in, on, or behind walls.
2. Heating panels shall be installed per the manufacturer’s instructions and in accordance with the product listing.
3. Heating panels shall be GFCI protected.
4. Grounding means, such as copper braid, metal sheath, or other approved means, shall be provided.
5. Heating panels shall be AFCI protected.
6. Heating panels shall be permitted to be installed no more than 1.2 m (4 ft) above the floor.

Exception: Low-voltage heating panels shall not be required to be GFCI protected.