How to fix a leaky radiator and stop unwanted water damage

Pink cloth being held under leaking radiator valve
How to fix a leaky radiator is a query many DIYers have in their home (Image credit: Getty Images)

You’ll want to know how to fix a leaky radiator if your central heating suddenly springs a leak. 

If you don't stop the leak as soon as possible you could cause serious water damage to the floor, damaging flooring or carpets. If the leaky radiator is upstairs, the water may also leak through a ceiling or even worse – into an electrical outlet. Plus, if you can’t fix it quickly you might have to go without water for a while and pay an expensive call out charge.

Small leaks are easiest to fix, it might be that you have been trying to work out how to bleed a radiator and when finished you didn’t tighten the valve enough. It could even be as simple as tightening a nut. But if not you need to get on the case quickly to stop the problem becoming worse.

Here we give you the lowdown on how to identify a leak, how to fix it and how much a professional will cost.

Steve Jenkins

Steve Jenkins is a freelance content creator with over two decades of experience working in digital and print and was previously the DIY content editor for Homebuilding & Renovating. 

He is a keen DIYer with over 20 years of experience in transforming and renovating the many homes he has lived in. He specialises in painting and decorating, but has a wide range of skills gleaned from working in the building trade for around 10 years and spending time at night school learning how to plaster and plumb.

He has fitted kitchens, tiled bathrooms and kitchens, laid many floors, built partition walls, plastered walls, plumbed in bathrooms, worked on loft conversions and much more. And when he's not sure how to tackle a DIY project he has a wide network of friends – including plumbers, gas engineers, tilers, carpenters, painters and decorators, electricians and builders – in the trade to call upon.