How do I balance a radiator circuit? A The first step is to try balancing the radiator circuit - a simple operation which British Gas does not seem to offer its customers. But it is quite easy to do, and you might even be able to manage it yourself. Each radiator has two valves, one of which has a tap-like head - the on/off valve. At the other end of the radiator is the balancing valve, which can be turned using an adjustable spanner, once you have prised off the plastic cap. Start by turning all the on/off valves anticlockwise, so that they are fully open. Then turn the balancing valves on the hottest radiators clockwise so that they are fully closed, and then open them a tiny bit - say one-quarter of a turn. Then it's just a matter of carrying out minor adjustments to each radiator in turn, so that heat is evenly distributed throughout the house. Q Having followed your advice regarding using central heating throughout the year, and being extremely pleased with the results, I would now like your opinion on reflective radiator panels. One advertiser claims that fitting these reflectors can save up to 20 per cent of heating costs, and that the capital outlay can be recovered in less than a single winter. Are these claims reasonable, or just a publicity gimmick? EA, by email A Personally, I'm very sceptical. A useful rule-of-thumb is that around 30 per cent of heat is lost through the roof, 20 per cent through the walls, 20 per cent through the windows, 15 per cent through the floors, and 15 per cent through air leakage. So suppose you covered all your external walls with reflective panels, and suppose these panels made the walls completely thermally efficient (which they wouldn't). Then you might save about 20 per cent of your heating losses. But reflective radiator panels only cover a small area to the rear of each radiator - possibly around 10 per cent of the wall area, if that. So even if they reflected all the heat incident upon that small area, it is very hard to see how they could save you even a fraction of what the manufacturers claim.