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 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, 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.
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 might not be the most convenient place.
More of a consideration is where your furniture is. 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.halfords.com, 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 floor covering make getting to the pipes harder.