Central heating boilers.

[Merry]

We`ve got a really old gas C/H boiler that runs our radiators and hot water. We`ve got all the insulation possible and we don`t keep our house over-heated..Put on a woolly if it`s nippy.
Our eldest is a heating engineer and he`s nagging us to have a new super boiler and new radiators.
The thing is, even though we`d only have to pay the cost of the equipment. Laddo would do the work free for his aged parents , it would take a big lump of our savings. Are we being environmental baddies if we keep the old stuff or can we just go on being as frugal as possible?

[Martin]

to be frank, to actually work out the environmental footprint of a boiler change is enormously complicated, because you have to somehow factor in the cost to the environment of the manufacture of the new items
My thought would be to look up your old boiler's efficiency, and if it's very low, change for a new high efficiency one - old boilers may use nearly twice as much fuel to achieve the same amount of heat output - do your own sums!

[Muddypause]

Martin's right (I don't always say that, y'know). If you actually needed a new boiler, then get a modern condensing boiler. In fact in the UK you don't get the option now; that's what you'll have to have. For the moment, if it was me, I'd continue using the old one until it dies.

Boiler manufacturers claim impressive efficiency for the condensing boiler - 80% or more - but an engineer friend of mine tells me that this is a maximal figure, and will only be achieved if you have the boiler working to its maximum output. Efficiency drops if the boiler is not used to its full.

Also, because they are more complicated, the service interval is generally shorter (six months, instead of a year), and the life expectancy is shorter - though they haven't really been around for long enough to be accurate about this, and as manufacturers come to grips with the technology, standards may improve. But to work out an accurate environmental footprint I guess you should factor in the extra journey that the service engineer makes each year, and the fact that you may be replacing it sooner.

[Merry]

Thanks Muddy, the old boiler works very well at the moment. I reckon I`ll hang on being frugal for a while. We only have it on in the coldest months. Again - thanks for the advice.

[greenbean]

Hi there, I am in no way an expert but my OHs cousin who is a plumber/HVAC chap installed our new boiler 2 years ago, he said a condensing boiler is best, but said to us that servicing only every 2 years or so is necessary - we had to get a new boiler as the one we inherited with the house was cr*p

[mew]

Just like to add a word or two on new boilers. If your going to replace an older boiler soon then don't! Over the next 18 months to 2yrs you'll see some boiler manufacturers coming out with a new kind of boiler which generates electricity too!. It takes a tiny amount of extra gas but it produces around 1Kw of electricity as well as all the hot water and heating. The company which has developed the technology is [url]www.microgen.com[/url] and so far the only domestic boiler company to take it on (as far as I know) is baxi/potterton. Its still in field trials at the moment but it looks like a belter of a boiler system. The main benefit being you are usually at home when your heatings on, and consequently the electricity is being produced when you need it and because its made at home the massively inefficient national grid isn't needed (mostly).

[Stonehead]

Just like to add a word or two on new boilers. If your going to replace an older boiler soon then don't! Over the next 18 months to 2yrs you'll see some boiler manufacturers coming out with a new kind of boiler which generates electricity too!. It takes a tiny amount of extra gas but it produces around 1Kw of electricity as well as all the hot water and heating. The company which has developed the technology is http://www.microgen.com and so far the only domestic boiler company to take it on (as far as I know) is baxi/potterton. Its still in field trials at the moment but it looks like a belter of a boiler system. The main benefit being you are usually at home when your heatings on, and consequently the electricity is being produced when you need it and because its made at home the massively inefficient national grid isn't needed (mostly).

Microgen's Stirling Engine microCHP isn't the only technology - there are also versions using fuel cells, Rankine cycle engines, and closed cycle steam engines.

And while the Microgen microCHP technology is a big improvement on most gas boilers, it's fuelled by natural gas - which is a finite, fossil fuel. So, instead of cutting gas use, it's simply a new means of achieving higher efficiency from a fuel-burning system.

BioCHP systems, which can be found in use in Europe, also have very good efficiency but, as they use renewable biomass for fuel, have drmatically lower life cycle CO2 emissions than gas microCHP. I'll have to dig out the exact figures but biomass microCHP produces about 1.5 tonnes of CO2 a year from a typical British 3-bed house with high levels on insulation while gas microCHP produces about 4.5 tonnes.

But the problem still remains - people are not curbing their energy use. Take a look at this story on BBC News (okay, three years old but still valid) about Power from the People.

The bloke who has a MicroCHP unit in his garage had been cutting back on his electricity use because of the cost. But now, he says he can generate electricity as the microCHP unit heats the house and not pay for it. Doh! He's still paying for it (in gas), plus he's using energy he would not otherwise be using. Grrrr!

[mew]

Thanks for the info, you'll be glad to hear that Microgen are also developing a version that uses biogas as well!

[Merry]

Thanks for the interesting technology info. I can see that the discussion/decision is far from simple - although it is very much affected by my limted available capital!