Is It Cheaper to Switch my Heating Off on Holiday?
In summer, if there's no risk of frost, you can generally turn your boiler off completely, especially for longer trips. This is recommended if you won't need heating, and if you have a combi boiler, and you won't need hot water until you return.
For system/regular boilers, the stored hot water will cool, but you can just heat it up when you get back. Yet, the exceptions here are if you have any concerns about damp or want to ensure minimal air circulation. Leaving it on a very low setting might be considered, though this is less common.