Plumbing / shower question

[Over Clocker]

Hi guys,

I've just replaced our shower pump as it kept cutting out.

Now, for both the old pump and new ones, they should be connected using the supplied 22mm hoses.

When I removed the panel I found the old pump had been connected using smaller 15 or 18mm hoses instead. The supply pipes are both 22mm, and the pipes leading to the taps are also 22mm, but they've been reduced down in size for the hoses.

For speed yesterday I've used the old hoses as I didn't have time (or a large anough spanner) to undo the connector on the pipe.

Should I revisit this and change the hoses to the 22mm ones or does it not really matter?

Thanks,
Mal

 

[BigBoy]

Are you sure it's 22mm and not ¾ tap connector you need?

 

[NickK]

I looked at flex hoses (braided or plastic?) for my shower install.

15mm braid flex pipe has an 8mm inside diameter construction at one end.

22mm braid flex pipe has a 13mm inside diameter constriction.

Seems only the “copper stick” flex copper pipes provide full bore.

Also ensure you use full bore isolation valves too..

A picture would probably help identify things better.

 

[MissChief]

It's possible the pump kept cutting out as it was tripping thermally. Many of them use the flow of cold water to cool themselves and it's possible the pump was being starved of cool water and overheating or not receiving enough flow due to the undersized hoses.

 

[Over Clocker]

Thanks guys.

Here's a picture with the old pump in place.



The two pipes coming up from the floor are the supply in larger pipework.

Thanks,
Mal

 

[Mercenary Keyboard Warrior]

You can get full bore flexi, 3/4" i had to buy for a water softner
At this level they are not that flexible though, they wont accept a tight turn radius

Check for full bore, they do exist, just hard to find, eg what I had to get

Easy way to get an idea of the bore, check the connector next to the fitting, on these its the same size!

https://www.ebay.co.uk/itm/QUALFLEX...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

 

[NickK]

edit: removed 3/4" to 22mm flex hose link..

edit: "12.5mm bore" hmm so those are no better than the 'standard' 22mm ones.

You can soon see if something is full bore - 22mm isolation valve - this is clear all the way through:

 

[NickK]

Thanks guys.

Here's a picture with the old pump in place.

The two pipes coming up from the floor are the supply in larger pipework.

Thanks,
Mal

That looks like a 3/4" into a 15mm (via 1/2" pipe?) into a 22mm flex pipe into a 22mm into a 3/4" pump connection? What does the specification for the pump say it needs?

If you have vernier callipers and measure the OD of the supply pipe - if it's bang on 22 then you have a metric pipe, if you have 7/8th inch (22.25mm upwards) you have imperial.

Either way - that stack looks overly complex and the 15mm is probably getting sucked hard.

You could probably change the supply to 22mm or 3/4 all the way through easily enough using screw or compression fittings. I'd recommend getting some "liquid PTFE" too either way - when you fit the PTFE tape use a small amount of tape then use the liquid PTFE, it will seal the screw threads once it's dried reducing leaks from metal threads.