HONITON firm Nu-Heat has signed a partnership agreement with one of the world's leading renewable energy product manufacturers.

Nu-Heat is the UK's biggest supplier of domestic underfloor heating systems. Its deal with Stiebel Eltron follows a trial of the German firm's products which saw heat pumps sales surge.

Nu-Heat's Adrian Troop predicted heat pump sales would double in 2010 as the green energy sector grows.