Gravity primarys

[Alfies Revenge]

can new heat only boilers still be fitted to a system with gravity primarys. Does it need to be a floor standing boiler?

 

[chrisey]

All new boilers fitted now have to be condensing and the hot water system has to be pumped and properly controlled with a cylinder stat and programmer. (Gravity systems are no longer acceptable) Regards chrisey

 

[croydoncorgi]

The pipework of the gravity system may be absolutely fine (even if a bit big!) and could be reused to connect boiler to cylinder.
In practice, you'll need a new cylinder (more lagging, high-efficiency coil).
Boiler is anything suitable for the proposed site and heat requirement. It's definitely a no-no to connect a condensing heat-only boiler to agravity system - even if the boiler would tolerate it, it would hardly ever condense and you'd never get most of the efficiency gain. Don't try it.