A heating expert has revealed the simple radiator hack could save you up to 25 per cent on your energy bills.

Engineering lecturer Peter Brown says a dirty heating system could increase your bills by a quarter and you can clear out the rust yourself or pay someone to filter out the 'sludge'.

He also revealed other cost saving tips that could keep you warm this winter.

Peter, who has lectured in engineering in Glasgow for ten years said a £15 inflatable draught excluder for an unused chimney can help the temperature climb indoors.

Radiator foil - which can be bought for around £7 - is also another top tip he gives for reflecting heat back into the room.

And while it may seem like an effort, tips which allow you to drop your thermostat by just one degree "correlates to a 10 per cent 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 your 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.

"Carpets are usually more effective at keeping the heat in than wooden floors, but laying a carpet if you don't already have one will not necessarily be more cost effective.

"An unused chimney can be plugged with an inflatable draught excluder, or you could pay a bit extra to get it professionally capped."

Peter says paying attention to your radiators can save you a lot on your bills.

"Investing in a roll of radiator reflecting foil is cheap and they are generally helpful at reflecting the heat back into the room," he said.

"Paying attention to the TRVs, which are the thermostatic valves controlling the temperature at the side of your radiator, is also important.

"Set the temperature in each room depending on how hot you want it - there's no need for your spare bedroom to be constantly heated, and generally sleeping areas don’t need to be as warm as living areas.

"Bleeding your radiators regularly is also a sure way to save some cash.

"Every one degree drop in temperature roughly correlates to a 10 per cent saving on your bill - aim to heat living areas to 21 degrees and bedrooms to 18."

If you're looking to fork out, he recommends making sure you'll see a return on your investment within five years and to get an energy assessment to make sure the changes are worth making.

"Take a look at the boiler itself, because it's very old, generally it will be insufficient, so forking out on a new condensing boiler will likely pay back fast," he said.

"Fuel prices have gone down a bit so you should be able to pay it back in five years.

“Wall cavity insulation has the quickest pay back time of anything, but you may not be able to install it in a period property, so the houses that need it the most may not get approved.

“Heating controls may also be a nifty investment as they can help heat your house by zone. Although it may set you back by £500-£1,000 depending on the size of your house.”