CH.These Things Are Sent To Try Us .

[Stuart]

Having just had a delivery from

including some 10mm copper piping etc I had an awful thought when looking at the pipe so went to look at the rad in the bathroom which I am renovating at present .I then went to look at all the other rads and what I have found is that ,contrary to my belief that the system was in 10mm ,it is a mixture of 10 and also 8mm .The rads in the hall,kitchen and one in the living room are in 10mm and the bathroom,both bedrooms and the other living room one are in 8mm .

Could there be a logical reason for this being done deliberately .

I don't know how I didn't notice this before .I'm sure I replaced a reducer before when I renewed a valve or two and used the new cap(s) so had to remove the reducer and I don't remember buying 15 to 8 reducers ...but then again,maybe I didn't replace them and just sawed off the olives to get the old cap off ... Aaargh...FFS

Stuart

[Roger Mills]

Assuming that you have individual feeds to each rad from a manifold, it sounds as if they have used an appropriate pipe size depending on the capacity of each rad. Presumably 8mm is cheaper. Why use 10mm when 8mm will do?

I must admit that it sounds a bit penny pinching!

[Mike Halmarack]

Sorry to hear about the problem but I was just about to start modifying what I took to be a number of 10mm radiator tails. Now I'm going to check carefully before ordering the materials. Thanks for the warning.

[Ed Sirett]

This is quite common on microbore systems. I presume that the idea is that bigger and further rads are given a bigger/wider supply and vice versa. The intention being to make the system better balanced by installation.

Note that you may find that 8mm fits snugly into 10mm pipe and can be soldered without additional fittings.

[Stuart]

Ths Ed ...What you say might explain me using 15-10 reducers on 8 mm pipe and it working OK ....Funny bit is that the bathroom is the furthest room from the boiler and also from the manifold which is in the hall and it is one of the rads that uses 8mm ....it is also the second largest rad at 600 x 1100 ,the largest is 600 x 1300 which uses

10mm ....as someone else said it does sound a bit mean ...why not just use all 10mm . Stuart

[John Stumbles]

But it's quite common, IME

[Brian Sharrock]

(In this post) you haven't given a date for when you believe the system was installed; but IIRC during the mid-seventies ~ early-eighties there was great difficulty obtaining copper tubing. My BCO advised me to install ABS (Poly-York) piping for my cold-water services and scrutinised the tubing specified for the CH circuitry. There was a strong incentive from the Government to minimize tubing sizes. My CH is a two-pipe system that starts off as 22mm; then reduces to 15mm finally reducing to 10mm as the 'load' decreases: Each radiator is fed with either 10mm or 8mm pipes as the surface area dictates.

To paraphrase; - There _Could_ be a logical reason for this being done deliberately it might have something to do with Belgian Paratroopers dropping into Zaire!

[Stuart]

Don't know exactly Brian but I moved here in 1984 and it was here then .

Stuart ..