Boiler installation in Cardiff — sized to your house.

Local knowledge

Fitting a boiler in a Cardiff terrace

Most boiler installations I carry out in Cardiff are in terraced houses, and the constraints are consistent enough to be worth explaining before anyone quotes. The boiler is usually in a rear kitchen extension or a side return, which limits where the flue can terminate. Building Regulations set minimum distances from boundaries, openings and adjacent surfaces, and on a narrow Cardiff side return those distances are the thing that decides the installation rather than any preference about where the boiler would look best.

Condensate routing is the second constraint and the one most often got wrong. A condensate pipe run externally on a north-facing wall in a side return will freeze, and the household will spend every cold snap with no heating. Where it cannot be run internally to an internal soil stack, it needs to be larger diameter, properly insulated and correctly fallen. It is a small part of the cost and the difference between a boiler that works every winter and one that does not.

On the question of which boiler: Cardiff's water is soft to slightly hard, so scale is not a factor pushing you toward one type or another. What matters far more is the incoming mains flow rate and how many bathrooms the property has. I measure the flow before recommending anything, because a combi that cannot be fed will disappoint whatever its rated output says. Where a terrace has been extended into a three or four bedroom house with two bathrooms, a system boiler and a cylinder is frequently the better answer.

Not sure which type you need? Which boiler do I actually need? walks through the three system types, the flow-rate test that decides whether a combi will cope, what the Welsh building regulations require, and the grants that genuinely exist here.