How level should the floor be before Underfloor Heating is installed?

The floor needs to be leveled before underfloor heating is installed. Failure to do so will mean an uneven distribution of heat when the underfloor heating is activated. If you want an even distribution of heat you need the heating cables on the same level.

Heatwell does put screed or leveling compound over our wires. However, the purpose of the screed is to set the cables in the place we want them, and to provide some protection for the cable before the final flooring has been installed. The purpose of the screed we install is not to level the floor.