Use a documented heated shower assembly for the exact pan and heating product.
The current Tile Redi yellow-pan installation instructions do not document an electric heating layer. Their illustrated assembly places tile and an approved thinset directly over the pan, with mortar below the pan. A general skim coat of thinset is not evidence that adding heating cable is approved.
Tile Redi’s current yellow-pan instructions allow specified white modified thinsets. Other pan families, including black Redi Your Way pans, have separate instructions. Identify the exact pan before choosing setting materials or proposing a heated assembly.
For a heated shower, use an assembly documented for both the shower system and heating product. The WarmlyYours TempZone shower-mat manual provides a mortar-bed installation sequence: fit and test the mat, embed it in the specified mortar while maintaining drainage slope, route the cold lead without tension, and install the secondary waterproofing membrane according to its manufacturer’s instructions. That sequence does not independently approve a Tile Redi pan.
Obtain model-specific written compatibility before adding heat to a pan whose instructions omit it. Tile Redi’s warranty depends on compliance with its instructions and approved materials; this article does not determine a particular warranty claim.
Sources: Tile Redi yellow-pan instructions, Tile Redi warranty and TempZone shower-mat manual (pages 7–8).