Replace the Cylinder or Convert to a Combi
When an old cylinder fails, homeowners often ask whether it's worth replacing like-for-like or taking the opportunity to remove it entirely and switch to a combi.
When an old cylinder fails, homeowners often ask whether it's worth replacing like-for-like or taking the opportunity to remove it entirely and switch to a combi. It depends on the household, not just the failed part.
The case for replacing the cylinder
Multiple bathrooms used at once, or a household that values strong, simultaneous hot water at several outlets, are better served keeping stored hot water than losing it.
The case for converting to combi
A single bathroom, low simultaneous demand, and a desire to reclaim the cylinder cupboard space make combi conversion a genuine simplification for the right household.
Which wins when
Usage pattern decides it, not the fact the old cylinder has failed. Converting a genuinely multi-bathroom household to combi to save cupboard space usually causes more frustration than it solves.
Questions we get asked
Is converting to combi cheaper than replacing a cylinder?
It varies by property and isn't something we'd quote without seeing the job, but cost shouldn't be the only factor — usage pattern matters more long-term.
Can I convert back to a cylinder system later if a combi disappoints?
Yes, though it means finding space for a cylinder again, which is easier to plan for now than to retrofit later.
Does the boiler need replacing to convert to combi?
Usually yes, since a combi is a different appliance type from a system or regular boiler, not simply a different pairing with the same unit.