Boiler Repair in Cardiff

A lot of boiler advice written for the UK market is written for hard water England, and it does not describe what actually goes wrong here. Cardiff's water comes off Brecon Beacons sandstone and shale rather than chalk or limestone, and it is soft to slightly hard. Limescale exists but it is a minor factor. If your boiler has failed at eight or ten years old in Cardiff, scale is very unlikely to be the reason.

What we find instead is magnetite — black iron oxide sludge produced as steel radiators corrode from the inside. Cardiff's terraced housing stock has a lot of original steel radiators and older pipework, systems that have been drained and refilled repeatedly over the years, and often no inhibitor left in them. The sludge collects in the heat exchanger and the pump, causing the symptoms people usually describe as the boiler "kettling", radiators cold at the bottom, or heating that works until it suddenly does not.

The second thing we see constantly on Cardiff terraces is siting. Boilers are very often in a rear kitchen extension, which puts the condensate pipe on an outside wall in a narrow side return. In a cold snap those freeze and the boiler locks out — a fault that looks alarming, costs nothing to fix, and can usually be prevented by lagging or re-routing the pipe. Before you replace a boiler on that history, it is worth having someone check whether the system is the problem rather than the appliance.