What is the average cost of an underfloor heating installation? Date: May 26, 2016 - 10:56 pm Vote Up 0 Vote Down Answered Public Underfloor Heating Central Heating NZ asked May 26, 2016 1 answer Vote Up 0 Vote Down Public Central Heating NZ ⋅ Staff ⋅ May 26, 2016 On average underfloor heating installation for 100 square meters, if run on gas will cost 11K. If run on heatpump $14K #1 Please login or Register to Submit Answer