Boiler sizing query

[Riley]

Morning chaps

doing a house renovation and customer lives abroad so is dealing with everything long distance. The property in question is a decent sized three bed semi with an almost completely open plan downstairs.

Definitely needs a new new boiler as existing is a 15 year old ariston and is not healthy.

There is an existing 150l unvented which will be staying as its a relatively new one.

Customer has asked that boiler be replaced soon as, as house is freezing at the moment and he is worrying about potential frost damage. He's one of these that likes each room to be quirky and different so he is looking to pick out his new radiators upon his return to the UK. I've sized the rooms etc but I think I'm going to end up with a load of oversized radiators because he likes the look of them.

This being the case I'm struggling to size a boiler. There will be 11 decent sized radiators and the cylinder. So I was thinking around the 24kw mark to take into account any potentially larger rads. Would you agree or would you go bigger? Cost is no object as owner is minted. Just wants it done so that the house is toasty.

Would appreciate your thoughts

Matt

 

[Riley]

Should've said was looking at a system boiler

 

[kozak1968]

Whole house boiler sizing online. Just put in the details and it will work it out. Or the old fashioned way with the sheet you are given when you done your part L.

 

[Riley]

Yeah sizing wise I've done that however I know the owner is gonna get some posh oversized radiators. So I don't want to end up with a boiler not powerful enough to warm all of them sufficiently. I'm kind of in a catch 22 need to do boiler asap but am reluctant until I know the size of these rads I'm going to be asked to fit.

Would you wait??

 

[Chalked]

It won't matter about the over sized radiators, it's the room your heating. Do the calculations as you normally would do.

 

[Ch4 plumbing]

Either wait or give the guy your heat loss per room and tell him he needs to stick to them? If he goes mad with over sizing then that's his problem! He will soon moan if you fit in 2 - 30kw boilers on a LLH in his kitchen just to be sure there's enough.

But out without looking I would think a 24kw boiler would be fine.

 

[Riley]

That was my general thinking. It's a small unvented so a lot of its generally going to be the rads.
Cheers

 

[Riley]

That's true chalked sorry hadn't thought of it like that. You're right

 

[jtsplumbing]

Put in another Ariston you can down rate them as low has 5Kw so you could put in a 30Kw that would allow for any future expansion to house then down rate it to required output

 

[gasmanrob]

Put in another Ariston you can down rate them as low has 5Kw so you could put in a 30Kw that would allow for any future expansion to house then down rate it to required output

In all my years I never thought I'd see anyone recommend re fitting an ariston surely the bloke has been punished enough once already

 

[Riley]

You can down rate most boilers

 

[jtsplumbing]

In all my years I never thought I'd see anyone recommend re fitting an ariston surely the bloke has been punished enough once already

He hasn't done to bad its lasted 15 years !!

 

[Riley]

Yeah I was impressed

 

[IDCHAPPY]

In all my years I never thought I'd see anyone recommend re fitting an ariston surely the bloke has been punished enough once already

Must be the drugs Rob :lol:

 

[IDCHAPPY]

26kw Vogue system .
An Ariston is another boiler I've fitted.... is there no end to my shame

 

[arran197]

I'd say anything over an 18kw should be ok.