will Vaillant Ecotec Pro 24 work for this house?

[bluesky]

hi all, just got the ticket really, really need some advice, this is a 4 bed detached house, built in 70s, one bathroom only, 3 sinks, i put details in the sedbuk website calculator, the answer is 19kw, is this calculation ok? some people said at least 30kw, who is right?

cheers in advance

 

[armourer]

This answer might upset a few people but I always oversize boilers.

The reason being (in my mind at least) is that a bigger boiler will always modulate down and this allows the boiler to tick over happily.

I liken it to a car. if it is running flat out (max output) then , yes it can do it but it wont last very long but if you have a bigger car that can give you the same speed but ticks over at lower revs it will last longer as it is not running at maximum output.

That said. That's how I look at it but welcome other opinions.

Also of course normally with bigger output boilers you have a better dhw flow ate.

 

[EPH]

19kw does seem a bit low, have you upgraded all your insulation in loft and cavity, as well as double glazing?

 

[andyplumber]

19kw does seem low for a 4 bed detached. there are a few things you need ask the customer before you fit a new boiler ask if they intend to fit anymore radiators in the future, add anymore bathrooms are they going to extend at any time if they are always size the boiler to suit for future needs like armourer said boiler modulate down on the heating side only the hot water runs at full rate. A 24KW boiler will run 18-20KW heating 24KW ho****er a 28kw boiler will run at 24kw heating and 28kw hot water and bigger the boiler, better the ho****er output which is what most customers want.

 

[jtsplumbing]

With any combi allways look at the hot water demands for the house 24Kw for average house heating is OK, but allways ask about hot water, try to keep pipe runs as short as poss for hot water, and check gas supply combi`s love 22mm again all about hot water ! best of luck, not often i fit anything less than a 30Kw.

 

[stevetheplumber]

with a combi its about the hot water rather than the heating output unless its rental property id always go for a 30 kw ,24kws struggle in winter to provide enough hot water