Condensing Gravity Boiler - do they exist?

[flutterbye]

Having seen the light, we're having our dangerous boiler replaced.

Its currently a gravity hot water with pumped heating and no valves. Are there any condensing boilers that are compatible with this or must I upgrade to a fully pumped system with M-valve etc?

 

[flutterbye]

Ok, I think I've fond the answer - its "no".

Seems I'll need to upgrade to a fully pumped system.

 

[Tipper]

When you replace a boiler you have to comply with the building regulations and that requires a fully pumped system and control valves, thermostats, etc......except if there are overriding reasons not to, ie can't physically be done.