Heating is a church's single biggest carbon emitter, so it is the first thing a decarbonisation plan deals with. It is not the whole building, though. Hot water for the kitchen, the vestry and the toilets usually runs off the same gas supply, and a church taking gas out needs an answer for both.
Air source hot water
If your church is removing gas, an all-electric path exists that covers heating and hot water together. Air source hot water cylinders pair with infrared heating to do it, and used with a green energy tariff that combination leaves no carbon from either.
The cylinders run on a different principle from an immersion heater. Rather than heating water directly, a built-in compressor extracts ambient warmth from the air around the cylinder and moves it into the water, which is why the energy going in is a fraction of the heat coming out. They use R290, a refrigerant with a very low global warming potential.
Tansun's own range is the ASWH80 series, designed and manufactured in the UK like the rest of its products.
Where it fits in a plan
Taking out gas is a decision about the whole building, not just the heaters. Worth working out early whether hot water is on the same supply, because it changes what a full all-electric scheme looks like and what the power supply needs to carry.