boiler sizing

[novicegas]

So, three bed two up two down type, terraced, 1960, double glazing, roof insulation. Worcester Bosch say 12ri Vaillant say 428. So is it a 28kw or 12kw?

 

[lame plumber]

not sure of the models but heat only/combi or system, what do your whole house calcs tell you to use?

 

[dancinplumba]

Why not a combi ?

 

[lame plumber]

Why not a combi ?

meant is he quoting for heat only orsystem or combi, as a 12w heat only is fine as would be a 28kw combi but I dont tougch wb/vaillant installs as I only use one make of wall hung boiler

 

[novicegas]

Just replacing an open vent for like, cust doesn't want combi.

 

[dancinplumba]

Choose a smaller vaillant rather than worcestershyte. 415 or 418 ?

 

[AlexGas]

For regular boilers, use one of these :

http://www.citygasservices.co.uk/res/pdf/ce54.pdf

... and Bob's your uncle.

 

[bewsh]

The 428 is probably too big for that property. I'd go for the 418