Stick with Conventional Boiler or move to Combi?

[simond]

Well, what has opinion got to do with it?

You have your percentages, that is the difference when connected to a test jig and passed through the SEDBUK routine.

Would you buy a car because it did 0.3mpg more than the other one?

Would the manufacturing tolerances and your driving style make a difference to the lab figures?

A 4 series Vaillant is not as well made as the 6, 8 and 9 series, but will fit in a smaller footprint.

If you want solar, fine, but since Hot Water is only about 15% of your gas bill and solar struggles to address more than 11%, and it needs servicing etc and cannot be expected to last longer than 20-25yrs, the repayment time is infinite.

People are putting in solar systems because they want to; if you try and justify them financially or ecologically you will find them flawed.

I think you need to take some advice from Gordon Ramsey ; or a heating installer who has had the opportunity of meeting you, discussing your requirements, and seeing the site.

 

[Andy.T]

Sorry didn't mean to upset anyone.

I thought I was just asking a simple question really and I've not been getting any answers on here for a bit so I've done my best to show that I'm trying to find the answers myself by going and looking up figures in the hope that it will solicit something from you guys in the know.

I'm not set on solar but I can see it potentially becoming useful as fuel prices rise further but as either a system or conventional boiler could support solar at a later date that is sort of a seperate issue that I can think about later?

My question is/has been (once more with feeling)...

Are system boilers inherently more efficient and cheaper to run than conventional boilers?

Thats it really.

Cheers,

Andy

 

[simond]

The figures are there. But I am sure you can appreciate that in a 'real life installation' 0.4% would not be measurable.

Pressurized systems (which system boilers generally are) are very slightly more efficient than open vented ones. But you would only see this level of granularity in a lab.

Local installation variables (size of rads, pipework runs, insulation of pipes, type of controls etc) would make the percentage difference you are worrying about seem piffle by comparison.

That is why your question seems rather pointless. For instance, an open vented high efficiency boiler equipped with weather compensation controls would be significantly more efficient than a system boiler without. That would be measurable and would deliver actual savings (in the right environment).

 

[Andy.T]

Thanks again Simon, I'm really not trying to be a pain just looking for some thoughts from you guys.

I suppose what I'm really asking is...

...given that much of those installation variables will be remaining unchanged; rads, pipework, insulation, house size etc. ...

...and given that weather compensation controls etc. could be installed on either a Conventional or a System boiler...

...all that stuff aside, would a System boiler be expected to be cheaper to run than a Conventional boiler?

It's likely to be quite a bit more money if we go the Systems route so I need to understand if there will be any savings as a result of this or if the only benefits will be ease of install, maintenance and getting some space back in the loft.

Cheers,

Andy

 

[Norcon]

AndyT wrote

would a System boiler be expected to be cheaper to run than a Conventional boiler?

Simond has already answered this question if you read back !.
Perhaps you are becoming confused between a combi and system boiler.

 

[Andy.T]

Does open vented = conventional?

If so then yes I guess Simon has answered my question. Sorry about that.

If there is very little difference between the efficiency of the two then it seems I'd be wasting my money to convert a conventional (open-vented?) setup to a System boiler arrangement? Unless I want to pay quite a big premium for the benefit of having no tanks in the loft?

 

[Norcon]

Section 3 of this link gives a brief explanation............

http://www.energysavingtrust.org.uk/uploads/documents/housingbuildings/ce30.pdf