Is this bolier ok with this tank - advise please?

[beetlezeb]

We're looking into getting rid of our old back boiler and tank in the loft due to impending loft conversion.
We are looking at installing a Worcester 30 CDi system boiler and a 200 litre Albion indirect, unvented stainless steel tank.

We will have 2 bathrooms, kitchen and utility sinks and 4 bedrooms once the conversion is complete.

Does this sound like suitable set up?

Any advice would be grateful, Thanks Sam.

 

[snb]

i would probably go with a 250 lt tank as you have 2 bathrooms. If they both have baths then you may also need to consider an accumulator to achieve the hot water flow. I would get someone to calculate the whole house heat requirement as you maybe going with a boiler that is too large.

 

[clf-gas]

Ask your installer to check if water pressure and flow are adequate for a 42 cdi combi with two baths you may benifit plus cheaper install.

Have a look on the Worcester Bosch site

 

[bengasman]

30 kw is probably about twice what you need unless you got very big house or very poorly insulated

 

[beetlezeb]

Thanks for the replies guys.

According to the WB website, for my 4 bedroom, 2 bathroom house I need a 40CDi .

We will have 4 double B/rooms, 2 bathrooms, kitchen/diner, utility, livingroom, hallway.

Total of 14 rads.

TIA, Sam

 

[bengasman]

Unless my memory is failing, 30 cdi is a heating only boiler, 40 is a combi. System boilers are calculated on heating demand, combis on hot water demand

 

[clf-gas]

42 CDI Combi, two showers at a time or shower and tap.

 

[doitall]

Thanks for the replies guys.

According to the WB website, for my 4 bedroom, 2 bathroom house I need a 40CDi .

We will have 4 double B/rooms, 2 bathrooms, kitchen/diner, utility, livingroom, hallway.

Total of 14 rads.

TIA, Sam

Stick with the unvented cylinder provided the mains water can supply

 

[beetlezeb]

Sorry, I should have said 40CDi convensional.

 

[ChrisR]

Bear in mind the heating coil in the unvented can absorb 25kW or so, which you want it to be able to do for fast recycling, so don't go small on the boiler.
A big combi isn't so daft - they often don't cost any more than system boilers, and you can have a belting shower forever without the HW running out. For one of the bathrooms perhaps?

Yes, measure the mains pressure and flow, and be prepared to put in a new main from the road

 

[topgazza]

Thanks for the replies guys.

According to the WB website, for my 4 bedroom, 2 bathroom house I need a 40CDi .

We will have 4 double B/rooms, 2 bathrooms, kitchen/diner, utility, livingroom, hallway.

Total of 14 rads.

TIA, Sam

Sounds just like my house and I have an old,non condensing, boiler of 15kw thats copes very well indeed in my 4 year old unvented water system, installed for the same reason as yours. As Chris says mains pressure is important..I had a nervous 10 mins whilst the installer checked ours..phew...it was OK.

I love the mains pressure hot water, no pumps for the showers. Advice I have had here is not to go too large and 30 or 40 sounds hugely over the top....but to size up a bit anyway..I'm going for either an 18 or 24 and have them adjusted to match my needs..the price difference is not huge.

 

[beetlezeb]

Thanks for the replies .

Has anyone fitted an Albion unvented cylinder? Do they come with everything need to install them or are there likely to be "extras" needed?

Our mains pressure is very good so this shouldn't be a problem.

Cheers, Sam

 

[bengasman]

Our mains pressure is very good so this shouldn't be a problem.

Cheers, Sam

Now check the flow rate