Difference in gas bills between Band A and Band D boiler

[Brian23]

I am considering installing a non condensing gas combi in my home. The rating is band d and having spoken to the manufacturer it is 79% efficient. The Band A Condenser in their range is 89%. I was wondering what the financial difference in terms of gas bills would be say over a year? I have been told by a guy at work I'd save £20 a year with the band a I haven't a clue though??

I am a Gas Safe registered installer btw I understand that strictly we're not supposed to fit non condensers but there are plenty around and the way I see it is I can afford a Vaillant non condenser which it is or a band a Heatline or cheap as chips model!!

Thanks in advance.

 

[dcawkwell]

If the difference in efficiency is 10% then for every £100 of normal gas
bill you have you save £10. So £500 gas bill you save £50.

If there is nothing wrong with your existing boiler keep the boiler.

 

[dcawkwell]

You must be a pretty hopeless RGI if you dont know the answers to those questions.

Might also explain why you are apparently not earning the £25 -£45k that an RGI would usually earn so that you can buy a good boiler!

The monthly payments on the Ferrari mean there won't be much left
for a quality boiler.

 

[Agile]

Well I have a Vaillant boiler but drive a Ford.

Got to get the priorities right.

 

[simond]

The question was 'what would be the difference'.

If a boiler is 79% efficient band D;

And your bill is £1000pa

Buy an 89% Band A, your bill will reduce to about £875.

It's more than 10% difference because of the ratio of fuel wasted is greater.

If you add weather comp to your new boiler you can expect slightly improved savings.

NB: In order for your savings to be just £20 your gas bill would have to be around £180 a year. That would be good.

 

[Corgigrouch]

Is a boiler that boasts 89% efficiency band B?

If the system is not designed to work with a condensing boiler then the boiler will only be at it's peak efficiency for a small portion of the time that it is heating..

 

[ALEC1]

unlessyou use compenaation controls....

 

[Corgigrouch]

unlessyou use compenaation controls....

But then it won't heat the room adequately. Surly.

 

[ALEC1]

They wont over heat the room... they matches heat output to heat loss...

 

[Norcon]

ZZZzzzzzzzz yawn.

 

[Corgigrouch]

Surly if the radiator is not correctly sized for the reduced water temperatures that allow a steamer to work efficiently then the room will be too cold when the heat is really needed..

 

[Corgigrouch]

Anyway where is the OP gonna buy a new band d boiler from? and if he could would it really be cheaper than a new steamer?

 

[ALEC1]

compensation controls respond to deviations from set point by increasing the flow temperature...

 

[Corgigrouch]

OK, yes I understand that... But if you increase the flow temp, do you not increase the return temp and therefore mess up the efficiency? Forgive me If you think I'm being awkward but I have always endeavoured to try to reduce the need for high flow temps by increasing the size of the radiators. Or is my thinking now a little out of date?

 

[ALEC1]

no not at all

as the room temperature increases the flow temperature decreases with internal control..

over sizing radiators can only be beneficial...as they give out proportionally more heat at the same temperatures, so the flow temperature lowers quicker....