Ok, so assuming I had the same boiler as the OP which is 24kw, then it can power 88btu's of hot water and central heating?
Do I just assume it can pretty much power as many radiators as I want? But the hot water would suffer if we were to try and shower at the same time?
Just trying to get my head around it.
Any boiler size will be fine for the central heating of normal size houses.
a 32kw boiler still tops out at 24kw give or take for central heating.
The larger the boiler the better for hot water demand, ie a shower. But the downside is they modulate higher as well so when the central heating only needs a few kw it might only be able to go down to around 8kw for a 32kw or 4kw for a 24kw boiler, which decreases effiecency as a boiler prefers to be on for sustained periods rather than on and off all the time. So balance your needs between hot water demand and central heating efficiency.
Its closer to 82BTUs as well, but ignore that, use kw.
On radiators make sure you understand where the kw rating comes from before buying any.
There specced to delta 50c, which is too high for a condensing boiler.
The rating presumes a flow of 80c, return of 60c. You want delta 40c minimum.
The manufacturer will have the calculation you need to apply but it will roughly be 0.75 so a 2kw radiator is better suited as a 1.5kw radiator when used with a condensing boiler.
Im doing my house at a delta 35 to further ensure the boiler is running at peak efficiency and also to improve warm up times on cold mornings. For 35c its 0.63 so the 2kw becomes 1.2kw.
As you can see you soon need much larger radiators. There is no downside other than space required for going bigger on radiators.
I hope all that makes sense.
