HIDDEN sludge inside your radiator could be costing you £450 a year in lost heat, but there’s an easy fix.

As temperatures plummet, we will all be looking for ways to heat our homes more efficiently.

With the average energy bill now £1,834, one expert has a tip that could save you a quarter of it – £450.

The humble radiator is the workhorse of that task, moving hot water through its metal frame and warming the room.

But, over time our radiators can seem like they lose their strength and we wind up using more blankets every winter.

Signs of issues are often clunking or groaning sounds when radiators are on as air has crept inside, making them less efficient.

Getting an engineer to fix the system can cost around £300 to £500 according to Checkatrade.

But you can also fix it yourself, with a 70p tool that is able to give your radiator another lease on life and clean away the “sludge” that builds up.

That tool, a radiator key, can ‘bleed’ the unit of all the air that isn’t supposed to be in the unit, and it’s available at all major homeware stores.

There are plenty of other cheap ways to warm the home too.

One expert who lectured in engineering in Glasgow for ten years told The Sun a £15 inflatable draught excluder for an unused chimney can help the temperature climb indoors.

Draught excludes work to block cool air coming into your home from underneath the gap at the bottom of your doors.

You can get them for as little as £7.99 from stores like The Range, however, if you have a thick blanket you can roll it into a sausage shape and that will work just as well.

Radiator foil – which can be bought for around £7 – is also another top tip Peter gives.

Radiator foil goes behind your radiator and reflects any heat going towards it back into the room.

You can find fairly priced radiator foil in stores like B&Q, Screwfix and B&M.

And while it may seem like an effort, tips which allow you to drop your thermostat by just one degree ‘correlates to a 10% saving on your bill,’ he claims.

Peter, a faculty director of engineering at Glasgow Kelvin College, said: “It’s not just the expensive things that keep your heating costs down.

“If you are losing heat through your windows and can’t afford double glazing, closing trickle vents and buying draught excluders can be just as effective.”

“Underfloor insulation can be costly but cans of spray foam can be bought for a fiver and work successfully to fill the gaps letting out all of your heat.”

Other top tips come from That Property Guy on TikTok, otherwise known as Kyle Mattison.

He suggests checking and reprogramming all your thermostats, reducing the temperature on your thermostat by just one degree can save you over £100 a year, he said.

Mattison also says insulation is important, with closing your curtains to keep the hot air inside the home and draught-proofing your home.