We are often asked to give a view on whether it is time to change an older gas boiler and whether a new gas boiler will be a more energy-efficient way to produce heat.
There is a guiding principle as on most things – if it’s giving a lot of trouble don’t throw good money after bad! Boilers often tell us when they have reached their ‘sell-by’ date by becoming very costly to run. We’ll usually tell you when we think that they have reached this point.
Condensing boilers are considerably more efficient than the previous generations of boilers. But even these grew gradually more efficient. If your boiler is fed by air from the room (open flued) it is probably very old and inefficient. You can tell by looking at the flue from outside. If there are 2 tubes – one to let air in, one to let air out, often with one inside the other, the boiler is not open flued. Open flued boilers have little control on their gas/air mix and their combustion and so are not very efficient. With gas prices increasing fast, it would be wise to change an open flued boiler, but it’s less certain whether changing a room sealed (not open flued) boiler will save money.
With the possible exception of installations in houses that have been purpose built with a very high level of insulation, the jury is still out on the benefits of heat pumps. They are certainly very costly to install. I’m sticking with my boiler at present and, unless things change, when it is time to replace, it’ll be another gas boiler. The other alternative, hydrogen boilers, is very much in the development phase. However, with both hydrogen boilers and heat pumps we are ‘keeping an eye on developments’.