Immersion Heaters as Hot Water Backup
An immersion heater is an electric element inside the cylinder that can heat water with no involvement from the boiler.
An immersion heater is an electric element inside the cylinder that can heat water with no involvement from the boiler. As a backup it is genuinely valuable; as a primary heat source it is expensive to run.
Why keep one
If the boiler fails on a Friday evening, an immersion means the household still has hot water while a repair is arranged.
Element position matters
A short element heats only the top of the cylinder — useful for a quick sink of hot water; a full-length element heats the whole volume more slowly.
Scale and seizure
In hard water the element scales and the thermostat drifts. Elements can also seize into the boss if they have never been touched in decades.
Sort a failed immersion heater
Tell us the cylinder type and whether the immersion trips or simply does nothing and we will know what to bring.
Questions we get asked
Why does my immersion trip the electrics?
Usually a failed element allowing a path to earth. It needs testing rather than repeated resetting.
Can I replace an immersion myself?
The electrical connection and the cylinder work both need doing properly, and a seized element can damage the cylinder if forced.
Is it worth using overnight?
Only if your tariff genuinely favours it. We make no savings claim without knowing your tariff.