Mircobore + Combi Help and information on all topics relating to your central heating, air conditioning and ventilation issues.

[JabberUK]

Hi All,
I currently have a boiler with hot water tank in attic and microbore piping. I have asked Bristish Gas for a quote on a combi boiler. They tell me that they strongly suggest not using a combi boiler with microbore because as the system is pressurised, if anything goes wrong, you can not get to the pipes in the wall. They suggest replacing like for like with a more efficient boiler. £4000 in total.

Can I have some advise on this as we really want a combi. We hate the idea of heating up water and then not using it.

Thanks
JannerUK

[plumbbob]

Personally. I see no reason why microbore cannot be used with a combi boiler without any problems whatsoever. There must be thousands, if not millions of homes in the UK using small bore pipes - even 8mm.

How suitable your existing pipework is is not due to it's diameter, but rather to the condition and design of the installation. Specifically, microbore systems can be difficult to balance because of the small pipe size. Typically, some radiators can be red hot whilst others are cool or even cold. The larger the property, the more likely the problem. Pressurized systems obviously put an extra strain on the pipes which needs to be taken in to account, but this applies to all types not just microbore.

Frankly, I would get a second quote from an independent installer who may very well have different ideas.

[JabberUK]

Thanks for this. I have since spoken direct with WORCESTER and they have advised against using combi boilers with microbore.

[htg engineer]

Using their theory then Minibore would be preferred as you can run long continuous lengths with no joints - you can get coated minibore pipe.


htg