Are Condensing Boilers more efficient in real life?

[Paul Barker]

Virtually none of the customers I ever come across have the technical ability to correctly assess their consumption!

Most seem to think that the only indication of gas consumption is the monthly direct debit demanded by their supplier.

Tony

Yes one of my abiding memries of that spell down their last summer was the question "will you check my meter please" Many of the occupants down there have barely enough intelligence to survive. If it weren't for the state picking up the slate they would either gain intelligence and a will to help themselves over night or starve to death.

 

[nickso]

i saved a lot when i put my condensing combi in. but thats not really a surprise considering what was in before. i did rip out the lot and start again so its probably not a fair comparison either. still adjusting my payments after 2 years too.

BTW you didnt answer my text i sent you on wedsnesday paul.

 

[jamesdean]

The answer is ``not really`` because condensing boilers work most efficiently when the flow and return temperatures are below 55 degrees given the fact that most boilers are fitted to an existing system normally installed to`` whatever radiator that looks good on the wall`` specifications the condensing combi won`t , in fact be any more fuel efficient than yer old combi. Sorry. It only actually condenses on heatup.

 

[Joshuajoe]

The big selling point of condensing boilers is that they are more efficient and will therefore save you money by reducing your gas consumption.

Has anyone, who has changed their boiler from non-condensing to condensing, done before and after comparisons of their gas consumption? If so what reduction in consumption did they achieve?

PS I have also posted this on another DIY site - there is no need to post two replies.

Hiya, if you already have a condensing boiler in your home it's against the law to fit a none condensing boiler. And the answer to your question is YES, condensing boilers are far more efficient, choose SEDBUK rating A or B.

 

[jamesdean]

And the answer to your question is YES, condensing boilers are far more efficient, choose SEDBUK rating A or B

Really? how`s that then seeing as though you obviously fit loads and understand how they work.

 

[D_Hailsham]

As so many readers just seem to reply to the Topic Title, without bothering to read the main text, here it is again, slightly edited.

Has anyone, who has changed their boiler from non-condensing to condensing, done before and after comparisons of their gas consumption? If so what reduction in consumption did they achieve?

 

[jamesdean]

As so many readers just seem to reply to the Topic Title,

Mad that isn`t? people replying to the topic that someone has posted. It infuriates me. Inconsiderate I call it.

 

[D_Hailsham]

As so many readers just seem to reply to the Topic Title,

Mad that isn`t? people replying to the topic that someone has posted. It infuriates me. Inconsiderate I call it.

How to reply to DIYnot topics - a guide for the uninitiated

1. Read the Topic Title - (this is just a summary of the question)

2. Read the text - this will tell you more about what the questioner wants to know.

3.Post a relevant reply.

Got it?

 

[jamesdean]

1. Read the Topic Title - (this is just a summary of the question)

2. Read the text - this will tell you more about what the questioner wants to know.

3.Post a relevant reply.

Got it?

[/quote]

I take it that this is how you want your efforts to replied to and not the rules laid down by this Forum Some people may think it`s allowed to go off on another tangent and discuss other things that may have originated with the original question. It`s called diversity. nothing personal.

 

[Joshuajoe]

And the answer to your question is YES, condensing boilers are far more efficient, choose SEDBUK rating A or B

Really? how`s that then seeing as though you obviously fit loads and understand how they work.

Well seeing as though there is a lot of sarcasm in your text, i have fitted loads, obviously i don't apply the gas because i'm only qualified in Plumbing and Heating NVQ LEVEL 2 AND CITY AND GUILDS 6129 and 6089, and BPEC UNVENTED SYSTEMS. I CAN SPEAK WITH A LITTLE AUTHORITY ON THE SUBJECT!!!!!!!!!

 

[Joshuajoe]

And the answer to your question is YES, condensing boilers are far more efficient, choose SEDBUK rating A or B

Really? how`s that then seeing as though you obviously fit loads and understand how they work.

Well seeing as though there is a lot of sarcasm in your text, i have fitted loads, obviously i don't apply the gas because i'm only qualified in Plumbing and Heating NVQ LEVEL 2 AND CITY AND GUILDS 6129 and 6089, and BPEC UNVENTED SYSTEMS. I CAN SPEAK WITH A LITTLE AUTHORITY ON THE SUBJECT!!!!!!!!!

 

[snb]

when servicing boilers the analyser readings usually come out with around 75% for a late sebuk D non-non condensing but at worst 72%

condensing sedbuk A normally achieve between 89.5% and 91.3% and once up to temp the worst you get is 86%

sedbuk b best 86 to 89% and worst 83%

So even in non condensing mode the latest boilers still achieve higher effiecency figures than non condensing.

I have had a few customers who have said when the boiler has changed my gas consumtion has stayed about the same! but when probed a little more they always say "but the house is much warmer now"

 

[D_Hailsham]

Some people may think it`s allowed to go off on another tangent and discuss other things that may have originated with the original question. It`s called diversity. nothing personal.

I have nothing against diversity, but it gets a bit frustrating when it is obvious that some contributors just read what is in the Subject Line and base their reply on that, without bothering to read the main text. I guess I should have worded the subject differently.

 

[D_Hailsham]

when servicing boilers the analyser readings usually come out with around 75% for a late sebuk D non-non condensing but at worst 72%

condensing sedbuk A normally achieve between 89.5% and 91.3% and once up to temp the worst you get is 86%

sedbuk b best 86 to 89% and worst 83%

But what is the analyser measuring? If it is the combustion efficiency of the burner, that's a completely different thing from the thermal efficiency. And it is thermal efficiency (heat out/heat in) which is used when calculating the Sedbuk rating.

 

[Agile]

The efficiency indicated by a combustion analyser is a computed efficiency from the measured parameters.

But that is based on many assumptions and is the higest efficiency anyone is ever likely to ever see.

The quoted sedbuk figures are a much more representative example of what someone may obtain but yet again the best figures.

There is so much difference between what someone could get and what they do get!

There are still many who fill their bath from a combi boiler st the hotest setting and then add cold water. That means the boiler is not condensing much! Recently someone on this forum even told us that how it should be done!

If you want the best efficiency then you have to learn how to obtain it and apply what you have learnt.

External weather compensation is one of the best ways to get the best efficiency but as always it has to be set correctly.

Tony