If there’s one technology that’s currently dominating modern-day boiler manufacturing, it’s condensing, or what’s also labelled high efficiency.
And although this breakthrough came many years ago, it’s only now, in this period of global warming and eco-awareness, that condensing boilers have taken off.
It’s fair to say that most boilers today – when using a combustible fuel – make use of condensing technology. And it’s this which allows boilers to reach plus 90% levels of efficiency, whereas in the pre-second world war years, boilers would struggle to get returns of 50%. In other words, say a bucket of coal was thrown on a fire, half of it would disappear up the chimney and only half the heat would be used for the home.
Modern boilers nowadays have to reach at least band B on the SEDBUK scale. Band B means between 86% to 90% efficiency, but most boilers should ideally be rated within band A (90% efficient and over). The Building Regulations state that if a property can accommodate a band B, or A boiler, then one has to be fitted. The only real exception are back boilers which tend to be the only appropriate unit for certain cottages and terrace houses.
Basically a simple process, condensing is all about taking a double grab at the heat generated by the combustion of the fuel type. Most of the heat is of course produced by, lets say, a burning gas flame, but a large proportion is obviously locked in the exhaust gases. But if that can also be harnessed, then the units efficiency will rise.
Which is why condensing boilers have two heat exchanges which should, ideally, be from high grade stainless steel for maximum performance and reliability. One heat exchanger takes the heat from the flames, the other from the exhaust gases.
It is a great technology and has alone allowed boilers to make dramatic leaps forward in terms of efficiency levels, in a time of increasing energy concerns.
The downside of a condensing boiler is a practical consideration. The process of collecting the exhaust gases requires the boiler designer to consider two side effects. One, a liquid (condensate) is produced during the process and two, the exhaust gases, once exploited for their heat, need help escaping the flue (chimney).
So, a modern condensing boiler has to be fitted with a drain system to remove the condensate (causing siting issues and extra cost installing the drain) and a fan has to be fitted inside the flue to ensure the safe removal of the gases (extra cost again).
And the condensate drain had one unfortunate side effect when sited on an external wall; it can freeze in cold weather which causes the boiler to shut down. So a frost protection feature for a boiler is very important.
Condensing technology is here to stay and will improve even further over the coming years.
0800 327 7121
Lines open Mon - Fri: 07:30 - 20:00
Sat: 08:00 - 18:00, Sun: 08:30 - 17:00
* Offer available when you book an appointment before 31/8/14 and is available for domestic properties only. Subject to boiler installation by British Gas. Offer applied at point of sale, not available in conjunction with any other British Gas Boiler offer.
† You could claim up to £270 Cashback for a new boiler in England or Wales and up to £400 Cashback in Scotland - whilst funds last. The Government Green Deal scheme is subject to terms and conditions - visit http://www.decc.gov.uk/greendeal (12/13).
Read testimonials from
many of our satisfied
We immediately had a call to arrange quotes for our old boiler. The service made it so much easier to compare our quotes and I think we ended up with a good deal for a new Worcester Bosch Boiler. The engineer didn’t even want a cup of tea!
Mr Durkin, Winchester, 1 Mar 2014
Managed to get a great quote from British Gas and finally have a working boiler after all these years, was worth the cost!
Mrs Berriman, Windsor, 9 Feb 2014
You could save money with FREE Home Insulation from British Gas
- Cavity Wall Insulation can save you up to £145 each year
- Loft Insulation can save you up to £150 each year
- Free Cavity Wall & Loft Insulation survey of your home
Sat: 08:00 - 18:00, Sun: 08:30 - 17:00
Up to £270 Green Deal
- Save Up to £270 Green Deal
- Limited offer only
- Home owers can claim