Disable the heating in summer

The best way to be sure you aren’t using any gas or electricity for heating is to turn the heating completely off. Even if your user controls won’t bring heating on under summer conditions, your system might. For instance, if you keep your usual heating diary set and just rely on the thermostat to keep the heating off, your system may be warming up the boilers just in case. In one church with two services a week, we found the system was using 28 kWh even without heating any radiators, at a cost of around £9 a month (September 2022 prices).

We’ve given this 1 star, but depending on what’s happening in your building, it could be more. Radiators are a popular way of warming croissants in all seasons. You don’t want to disable the heating if it will lose you room hires or make people so cold they bring in space heaters, but in the current climate crisis, some communities will be receptive to the old British tradition of heating from October to May.

You might want to ask the manufacturer whether turning the boiler off for a few months will void its warranty or if there’s anything you need to do to ensure it will start again in the autumn. Modern boilers turn themselves on periodically for maintenance checks, but this doesn’t appear to do anything but flash an error code that you’re unlikely to notice until autumn anyway.

You may be thinking, “but what if the temperature drops suddenly?”
In stone buildings or buildings that are well insulated, rapid internal temperature changes are physically impossible. Remember that in the summer, the walls and other surfaces will be relatively warm. The building will be a steady and comfortable temperature given the right clothing, as long as it doesn’t have a cold wind blowing through it at the time.