Boiler size

[Cchrish0]

Hi all. Wondering if any one can help out. We are having a new grant external blue combi fitted on a project we are working on. The total rad kW is about 12000. There is one main bathroom with poss combi fed shower. An on suite with Elec shower, downstairs toilet and kitchen. Engineer is planning on fitting a 21 kW model. My concern is this may be a little small. Any advice would be great.

 

[SimonG]

Discuss your concerns with the engineer.

 

[Cchrish0]

Discuss your concerns with the engineer.[/QUOTE
Yes already done that, which is why I am purely seeking a second professional opinion.

 

[ShaunCorbs]

Normally combis are sized on hot water not heating but don't know if that's the same for oil

 

[Last Plumber]

That figure is not right !
12000 KW ?
Nope

 

[PhoenixServices]

That must be btus

 

[Ch4 plumbing]

I'm not sure they even do a 21KW combi?? might be wrong but I thought the smallest was 24KW.

 

[ShaunCorbs]

I'm not sure they even do a 21KW combi?? might be wrong but I thought the smallest was 24KW.

No they do do a 21kw blue

 

[Cchrish0]

That figure is not right !
12000 KW ?
Nope

Yes not 12000kw but 12000w/12kw

 

[Last Plumber]

Need to discuss it with installer as said before.

Discuss litres per minute of hot water and how many people live there that kind of thing.
I'd get a second opinion from someone who' s seen the job too. Before you go ahead. It will put your mind at ease

 

[Stoney Ground]

Or you could just ask him to put a 26 or 36kW and pay the extra.