Radiators

Cold spots at the top of a radiator almost always mean trapped air — a bleed key, two minutes, and it is sorted. Cold at the bottom usually indicates sludge build-up from corrosion in the system, or a failing circulator pump. A radiator that is hot at one end and cold at the other points to a balancing issue or a stuck thermostatic valve head. These guides walk you through every common radiator fault in UK central heating systems, from a single cold radiator to an entire zone that will not heat up, including how to power-flush, balance radiators, replace a TRV, and diagnose whether the problem is with the radiator itself or the boiler.