Microbore - 12mm central heating piping

richieboy · 10 Apr 2019 at 08:33

Morning,

We are looking at buying a place - built in 1995, that appears to have 12mm piping to all of the radiators, rather than the 15mm which we have in our current place. I didn't think this was a big deal but a friend of mine has 12mm microbore piping for his central heating and is constantly telling me it's a pain with blockages etc.

So my main question - does anyone think microbore would put you off a house entirely, make you want to offer less, or is it completely normal these days and absolutely fine?!

Cheers

sja360 · 10 Apr 2019 at 08:55

My brothers house has 8mm, and its been there for 20+ years (used to be our family home) and the system has been working fine.

I suspect if people don't have inhibitor etc in it the system will block up a lot easier than 15mm

I believe they are not using microbore pipe sizing anymore. Haven't they gone all plastic pipework these days ?

Jez · 10 Apr 2019 at 09:32

Microbore is very common (nowadays in plastic) and was used in some new builds which i was close to here. Its common enough that screwfix sell it in massive lengths for heating systems.

I have a retrofit microbore system in my older property which was installed around 30 years ago, it has never blocked and works fine.

robj20 · 10 Apr 2019 at 10:05

12mm will be fine i wouldn't want 8mm though.

Did my house in 22 and 15. I do however have 8mm for some of the hotwater pipes.

richieboy · 10 Apr 2019 at 17:12

Righto thanks all, sounds like I need not worry too much!

sja360 · 10 Apr 2019 at 18:22

Just ask to have the boiler system on and you can go around the property while viewing feeling radiators ensuring their heating and equally throughout.

Fluke? · 10 Apr 2019 at 19:21

We have 8mm microbore in our 70's house that we purchased last year. The homebuyer report picked up on it and said it was more prone to blocking than wider pipes but so far (touch wood) its been ok.
You can do things to flush the system if you're worried too.

Bat · 10 Apr 2019 at 19:45

All comes down to how well the system has been looked after, and where the pipes are if there are blockages.

I'd be looking for evidence of boiler servicing, and system maintenance. As stated if you are able to see the system working and all rads getting hot, then that at least confirms a flow all round.

If you buy it and there isn't a magnetic filter on the system, then I would strongly advise fitting one.

Kimi · 11 Apr 2019 at 07:53

Microbore is fine. You might find that it's running from a manifold.

Many new builds we go to are 15mm with 10mm running from them.

I've just done my whole upstairs in 10mm. Mine are all running back to a central underfloor heating style manifold. Works great and no flow issues what so ever.