Recommendations for condensing boilers, please

[jray]

Hi

We currently live in a 3bed house, one upstairs bathroom/wc and 2 reception rooms with seven radiators throughout. (The washing machine is in the kitchen). Our current boiler must be about 20-odd years old, with a tank in the loft and cylinder in a bedroom. Every so often OH has to top up something in the bedroom with water to stop the radiators making a whining noise.

We are getting a 4x3m grd flr extension with downstairs shower/wc done very soon (but not soon enough to beat the April deadline for conventional boilers I think), and so need to upgrade our boiler to a condensing one. I gather that combis aren't too popular with the experts on this board! The extension will have a dishwasher, washing machine, plus electric power shower in the shower/wc.

Rather than rely on the builder to recommend a boiler that might be convenient for him to install, I was hoping you could offer us some advice/comments please.

My questions are (a) what size boiler will we need? 18kw? 24kw? 37kw? will it fit in a 600mm wall unit? (b) will we still need the hot water cylinder in the bedroom and the tank in the loft? (c) will we be able to use the upstairs bath and downstairs shower at the same time without getting scalded or frozen? (d) is there anything else we need to be aware of, or boilers to avoid? (e) what's the best way to deal with the pluming from the flue?

A few questions there, but any help would be greatly appreciated!

Thanks in advance
Jackie

 

[kevplumb]

a boiler size depends on the load

b if you want to use two appliances yes

c see above

d in what respect

 

[jray]

(a) Hot water in upstairs bathroom and downstairs shower room, central heating with eight radiators, washing machine, dishwasher - is this what you mean by 'load', kevplumb?
(d) eg. are there any boilers that have a reputation for poor performance and reliability, are there any that have common problems (corrosion, fan, etc)

Hope this helps
Thanks

 

[kevplumb]

load as in heating/ hot water load in kw

personal opinion(and thats all it is ) stay away from cheap and italian/spanish (amounts to the same thing really)

worcester are pretty good

make sure its well flushed properly fitted and you get the benchmark book

depending on the configuration
ball park 28 kw (dont hold me to it) or i will deny this conversation ever took place

 

[jray]

Thanks for your reply, kevplumb.

Just looked on the Worcester site - are you talking about the Greenstar 28e model? I've read that stainless steel heat exchangers are less prone to corrosion than the aluminium ones. Do you know of any brands, eg. Vaillant, that have the stainless steel h/exchangers?

Re load - I used one of the boiler size calculators on the internet, and it recommended a boiler output of 11.98kw. Does that sound about right to you for a 3bed terraced with fair insulation?

Thanks in advance

 

[kevplumb]

did you allow for the hot water i would stick 10 kw on

a few have stainless h/e keston,vissiman

top end of the market tho and priced to match

i'll have a look about through my bumph

 

[jray]

Appreciate that, kevplumb. You've been very helpful.

Thanks

 

[kevplumb]

your right vaillant ecomax has a s/s h/e

next question

 

[jray]

Thanks .

OK...

What do you think of these condensing boilers? (Not sure if the hometec one is a combi, which we wouldn't want).

Vaillant Ecomax Pro
http://www.vaillant.co.uk/folder.ph...-10330-10473&folder_default_netfolderID=10473

Eco hometec
http://www.eco-hometec.co.uk/EC30.htm

Keston
http://www.keston.co.uk/products/c40c55.htm

Glow-Worm
http://www.high-efficiency.info/prod_details.asp?product_id=5

Couldn't find any for Worcester Bosch or Potterton, maybe their heat exchangers are aluminium?

Also, I'm reliably informed that the fumes from these boilers are really unpleasant. Is the best location (neighbour-friendly-wise) to have the outlet at roof level?

Thanks again

 

[kevplumb]

fumes dont really smell after the initial lighting

as for reccomendations if you wait till some of the regulars log on you will get a more balanced veiw

high level flue would be better tho

 

[COG]

The Greenstar range you mentioned are codensing boilers, they use a90% ali and 10% silica heat exchanger ,ive worked on this heat exchanger hear and abroad for years (wb5 heat ex) and have never seen any signs of corrosion if it was a problem i would not think Bosch would be spending millions on there boilers.

 

[jray]

Appreciate your help, kevplumb.

Looking forward to some balanced views from the other experts here!

Kind regards
Jackie

 

[jray]

Thanks for that COG. I know that Worcester Bosch is one of the more popular makes of condensing boiler ...

 

[htgeng]

If you want the best boiler, it will cost you more £££ upfront. But try to think of them as a long term investment rather than the cheap tat.

ATAG Blue Angel or Viessmann Vitodens 100/200 are the ones you should consider. Make sure you specify the boiler has weather compensation.

 

[jray]

Thanks, htgeng.

Funnily enough I'd never heard of either of those two brands until I was Googling just this afternoon. Are these both wall-mounted? I was looking at the Viessman (V???) 300 and thought it was a commercial boiler. Also, I'm a bit concerned about servicing and whether the bog standard emergency plumber would be au fait with servicing these makes.