Possibly in a situation soon where we’ll be adding a reasonably large extension to an old house. IN the new part of the house we’d ideally have wet underfloor heating.

All my research to date says to avoid new oil combi boilers due to cost and more importantly reliability.

For the extension I’d like to add wet underfloor heating if at all possible. Is it feasible to integrate this into an old (presumably)gravity fed system fed by an old school oil boiler?

If not are there any other proven solutions I should be considering?

there’s always ways to do it, but not enough info to advise – you haven’t even checked if there is a pump for the existing heating system.

I don’t like combi’s in general – if the boiler breaks down you have not heating/hot water. with a traditional hot water cylinder and boiler you can at least get hot water.

There is a difference in operating temps . Underfloor runs a a lower temp than radiators. It can be done, seen under floor running off wood burners etc just need a bit of tech to keep the temps right.

We have wet underfloor downstairs and radiators upstairs. A manifold downstairs controls the 4 zones.

It’s not been in long but works a treat.

Edit: old oil boiler system. I’m not keen on getting a combi either.

breadcrumb – sounds promising. i’ve spoken to a couple of underfloor heating firms and of course they say no problemo. good to hear of some real life examples

Absolutely no problem to do that

We’ve done exactly what you describe with a Nuheat system and an existing, non-condensing combi boiler and it works really well. I’m no heating engineer but I believe that it is the condensing part of modern boilers that makes them shorter lived than older boilers.

As long as your boiler is large enough to cope with the added demand of the extension there’s no problem. The biggest issue is the type of system you have, if it is gravity ( on the hot water side) this will need to be upgraded,you will also need to get the system rewired. It’s all doable though.

We have underfloor heating in a new extension that we hooked up to an old oil boiler. It didn’t occur to me it might be unusual and it didn’t phase the plumber.