Open the bathroom window or use the extractor fan when showering. Keep the bathroom door closed at all times, to prevent water vapour from showers circulating around the flat. Use a cooker hood (venting directly to the outside) when cooking every litre of gas burned produces five litres of water vapour. Finally, every home would benefit from use of a dehumidifier. Use it on the low, economy setting all the time, but turn it up when a higher moisture load is introduced into the house such as showering, cooking, or bringing damp washing into living areas. Ebac is a popular British-made brand with a good record, and they are offering a 20 per cent discount to Telegraph readers. Call 0845 634 1392 and quote the promotion code ASKJEFF. Incidentally, following my answer about external condensation on window glass, reader David Broome has suggested the use of a water-repellent coating such as Rain-X rain repellent, which is sold in motoring stores for use on car windows. I have no experience of this product myself, and would welcome readers experiences. Q. Further to your recent column on combi boilers, is it true that, at some time in the future, all replacement boilers will have to be combi boilers by law?
Having taken in your views on the subject this is a rather alarming prospect. MS, by email
A. No, this is not true. All new and replacement boilers have to be condensing models, which are slightly more efficient because they extract some waste heat from the flue gasses (although any efficiency gains are probably cancelled-out by the short life expectancy of these boilers). However, there is no need for a new condensing boiler to be installed as part of a pressurised combi system, and there are no plans for this to become a requirement in the future. Condensing boilers work just as efficiently in a traditional indirect-pressure system, with a hot-water cylinder and cold-water storage cistern. For some reason, many readers confuse the two words, combi and condensing, and that confusion is exploited by unscrupulous heating engineers and firms in order to sell combi boiler systems, which are much easier for them to install, and therefore more profitable. Q. Further to your recent discussions and solutions concerning heating and hot water, I have a further question.
Two of my friends have had Megaflo systems installed. What is this and how does it compare with the combi and the traditional heating systems? SA, London A. Megaflo is one brand name for an unvented mains-pressure hot water cylinder. It works in much the same way as a conventional hot-water cylinder, being heated by the boiler, or by an electric immersion heater. The difference is that there is no cold-water cistern to provide indirect pressure to it. Instead you are dependent on the mains pressure, and if this is poor it can lead to the same problems experienced by owners of combi boiler systems namely poor water flow to upper storeys, and interference with the flow when two or more outlets in the house are being used at the same time. Unvented systems are generally not advisable unless you have good mains pressure (at least 1. 5 bar) entering the property via a 22mm supply pipe. The cylinder also requires a yearly test and maintenance by a service engineer. If your house has an existing hot-water system fed by a cold-water cistern, then I cannot see any advantage in removing this and replacing it with an unvented pressurised system.
If the main aim is to get a powerful shower, then an electric shower pump is a cheaper and easier option. Send your questions to Jeff at Property, The Daily Telegraph, 111 Buckingham Palace Road, London SW1W 0DT, or email askjeff@telegraph. co. uk. Also visit Use exhaust fans and vents throughout the house. One of the best ways to get humidity out of your house is to vent it outside through exhaust fans. Using exhaust fans is important in certain rooms and with certain appliances that produce moisture. Use bathroom vents and fans when you\’re bathing. Run them for at least 20 minutes after your shower. Use kitchen and stove fans when you\’re cooking. Run them for about 15 minutes after you finish cooking. Make sure your dryer vents to the outside for when you\’re doing laundry. A gas fireplace must have a chimney that vents outside, and you should always keep the damper open when you\’re having a fire in a wood burning fireplace.