I've got a Potterton Suprima gas boiler at the moment which heats the hot water and stores it in an indirect cylinder. The central heating is via a pressurised mini-bore system which is no trouble at all. I've had it converted to remove the double valve and baffle pipe and each radiator has a flow and return at opposite ends (like they're supposed to!).

My boiler is getting a bit tired, so I'm thinking of replacing it with a combination. I know that this will get rid of the loft tank and the indirect, but will it be OK with the pressurised system, please, or is there a better way? Any strong preferences on the combo boiler itself?

TIA!

Ray

thescruff wrote on Apr 25^th, 2014, 1:46pm:


I assume it's the old single valve where the flow and return came to the same valve and one of them was extended into the rad with a bit of microbore.

TBOE top,bottom opposite ends.

BBOE bottom, bottom, oposite ends and the most popular.

TBSE top, bottom, same end not used much.

Hope that clears that up.

With any combi you need a good mains supply, and quite often the hot water performance is not as good as expected or as good as the existing but, it can be better and free up space at the same time, the installer should check the flow rate etc at peak and off peak times.

I didn't suggest you were installing it yourself and apologise if that was the impression.

yes you can change to a high pressure system without too many problems if any, the main thing would be to check Washing machine hoses etc are not old and worn, A ballvalve may be low pressure and need changing to high pressure but all obvious stuff your guy should be aware of.