Plumbing 22mm zone valve into 15mm pipe

15 Feb 2012
Reaction score
United Kingdom
I need to add a 22mm honeywell zone valve into a 15mm pipe that is both close to another pipe (about 1cm away) and close to the floor (carpet).

I'll be able to cut the pipe using a mini hacksaw blade and file the edge of the pipe etc, but what compression joints should I use?

Option A -
15mm pipe to 15-22mm converter ( to 22mm pipe to zone valve to 22mm pipe to 15-22mm converter to 15mm pipe

does that make sense?


using these in place of the converters above?

I don't want to solder and i'm tight on space. What is easier?

Sponsored Links
Option A will be fine. You just need a piece of 22mm to connect the motorised valve to the adaptor.

I don't understand the second option as it requires soldering. The name "end feed" refers to how it is soldered.
Simon, thanks for that. Look like the sort of thing but I can't quite work out how they work from that photo.

Can you please explain?

Thank you.
Sponsored Links
Assume your fitting is to the left of those parts, with it's open end pointing to the right.

Remove the nut and 22mm olive, slide the nut onto the 15mm pipe followed by the parts in the order shown. The longer brass bit now goes into the fitting which reduces the hole down to 15mm, while the shorter piece reduces the hole in the nut down to 15mm. And the 15mm olive in the middle seals onto the pipe.

From the perspective of the fitting, the ridges on the two parts are just like a 22mm olive. From the pipe perspective, the insides of the two parts are just like the inside of a 15mm fitting.

Very useful, and available in a variety of size combinations. One particularly common use is to fit 1/2" (15mm) radiator valves to microbore (10mm or 8mm) pipework - saves having to make & stock valve bodies in multiple pipe sizes.

That is most helpful, thanks.

As I am going to have to cut the pipe with a junior hacksaw, does the end of the pipe have to be perfectly square? Obviously the closer it is the better.... but this may be tricky!
It's not critical, but yes, it's better if it at least looks like you tried !
I have seen joints where the angle is so large that the pipe isn't fully into the olive on one side - and you wonder how on earth it managed to hold on for all those years :confused:

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local