Detached property, hosted by Roy

1930's house with insulated cavity wall. 300mm loft insulation. Full double glazing. The COP for heating seems to be around 4.5 - 4.9 with a flow temperature of around 32 degrees. Install took a whole week with about three days living using electric fans. Only one day without hot water. Three radiators were upgraded, all other plumbing was fine.

Costs seem to have fallen. We are on Intelligent Octopus Go as we have an electric car, this gives us 6 hours of 7p/kWh electricity (as per 2025) which we use to heat the hot water overnight at about a third the cost of gas. Heating is more similar to gas in cost as we have to heat in the daytime. Our Solar Photovoltaic system and battery storage help reduce the amount of daytime electricity that we use. We also save the £100 or so gas standing charge. Radiators are cool but keep up with the heat loss of the house. The Vaillant 10kW heat pump seems efficient and pretty noiseless.