REPLACING an old boiler with an energy efficient model is one of the best home improvements you can do, but it’s expensive and if you can’t afford it, could you benefit from changing the radiators instead?

If your home’s radiators aren’t as powerful as you’d like, the first thing to do is bleed them. Radiators containing trapped air are hot at the bottom but cold further up, so they’re not giving off as much heat as they should. Bleeding them is easy – simply put a radiator key or small screwdriver (depending on the type of hole) into the bleed valve on the radiator and open the valve to let out the air. This can make a big difference to how hot the radiator gets.

Another reason a radiator might be inadequate is if it’s not powerful enough for the room, or you need more than one. Radiator output is measured in btus (British thermal units) and to work out the btus required to heat a room, ask a plumber or use an online btu calculator. Calculators vary, but they should factor in the dimensions of the room, the type of room (living rooms need to be warmer than bedrooms, for example) and things like the number of outside walls and the type of window glazing. Some btu calculators take account of more factors than others, so you may get different results. They may also give a range of btus for the room, rather than one figure.

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When adding radiators or fitting more powerful ones, check the capacity of the boiler. If the boiler’s a modern combi, you shouldn’t have a problem, but ask a heating engineer if in doubt.

Radiators were traditionally fitted under the window because this was the draughtiest spot and where most heat escaped. With more energy efficient windows, this is less of an issue, and it may not be the most convenient place. More of a consideration is the siting of your furniture. You don’t, for example, want a radiator heating the back of the sofa, rather than the room. In this case, it’s best to move the radiator or swap a horizontal radiator for a vertical one, which will take up less space at sofa level.

While you can treat rust (use Hammerite Kurust, RRP £8.49 for 250ml, available from, an easy-to-apply liquid that quickly turns rust black so it can be painted), once radiators start to rust, it’s generally time to change them, certainly if the rust might cause them to leak. Replacing old radiators may be something you want to do anyway to get more powerful ones or ones that look nicer. You can often get smaller modern radiators with the same or a greater output than your old ones, because the materials and technology used today are better.

If you’re changing the number or position of the radiators, this will be more expensive than swapping them like for like, as the plumber will have to alter the pipework. This is easy to do with exposed original floorboards, because they can be taken up, but other types of floorcovering make getting to the pipes harder. For this reason, it’s sometimes better to change the radiators when doing other home improvements, but if this winter proves to be a cold one, you might not want to wait.

The Northern Echo: how to

How to…

BECAUSE radiators should be cold and turned off when you paint them, it’s a really good idea to use quick-drying radiator paint at this time of year when you might want to put the heating on. The trouble with a lot of these paints is that the texture makes it hard to get a good finish, but not with Hammerite Quick Drying Radiator Paint in Satin White (RRP £9.95 for 500ml, available from, which is low odour and nice to use.

For the fiddly bits, where it’s not easy to use a paintbrush, or for column radiators, which are awkward to paint with a brush, use a specialist spray paint, such as Hammerite Radiator Enamel aerosol in Smooth Satin White (RRP £8.80 for 400ml, available from This tough paint also dries quickly – do as many thin coats as you need, rather than one thick one, because the paint may sag and run. Both these paints are designed to resist yellowing – if you use normal white metal paint, the heat from the radiator will turn it yellow over time.

Product of the week

THE Really Big Roller Box by Harris (£29.99, Screwfix, is great value and has everything you need to get rollering. You get two paint trays, a tray insert (dried paint can ruin the tray, so it’s easier to use and then bin the insert), a useful tray cover, an extension pole for doing ceilings easily, two roller cleaners, three roller frames (a small, medium and large) and different types of roller sleeve to fit them, so you’re not stuck if one’s in use. The sleeves give a really good finish, but the frames are the stars of the show because not only are they rubberised, they also have finger and thumb grips so you don’t get sore hands. If you have a lot of decorating to do, this kit is a brilliant buy.