The MCS figures come with the following caveats:For the purposes of answering this question, “low-carbon heating systems” comprise (i) Air Source Heat Pumps, (ii) Biomass, (iii) Ground/Water Source Heat Pumps, (iv) Micro CHP, (v) Other Heat Pump Types, and (vi) Solar Thermal.MCS certification is not a mandatory requirement, so MCS data does not capture all ...