New System Boiler 624/630

[topman870]

Hello Chaps,

My friend is having a new boiler fitted and the plumber has suggested to install a vaillant 630 due to a large house instead of a 624. Ground floor is about 85 sq meters of UFH and upstairs has 4 large double rads, and a hot water cylinder.

Currently the boiler is located in the loft which has a 22mm gas pipe going up from the ground, will the gas supply be sufficient for the 630 or will it need to be changed to a 28mm?

Thanks!

 

[muggles]

85sqm of UFH is about 8.5kW. 4 large rads, say 1.5kW each so that's 6kW, total heat load 14.5kW. Add 3kW for a cylinder and that's 17.5kW, so a 24kW boiler is massively oversized let alone a 30kW, which is just silly. It'll cycle like Bradley Wiggins and be much more expensive to run. Sounds like your friend needs a new installer who actually understands his job. An 18kW boiler would almost certainly be adequate.

Impossible to say whether the current gas pipe will be sufficient - need to know length of run, number of bends, power and location of any other gas appliances etc etc

 

[topman870]

Cheers Muggles! I'll be advising him to look for a new plumber!! Bloody cowboys!

 

[muggles]

Cheers Muggles! I'll be advising him to look for a new plumber!! Bloody cowboys!

If you post his location (nearest town) we might be able to recommend someone...