Shower pump - flexible hose

[jtheobald]

Hi,

I want to replace some 15mm copper pipe which runs across my attic floor (approx. 10m) for 22mm. The pipe goes form a shower pump in the airing cupboard to an en-suite shower.
My question is can I replace this copper with a flexible Polybutylene?

Is there any disadvantages and what do I need to consider?

I understand I will still need elbows etc. Also the shower pump (Stuart Turner) already has flexible hoses so how will I join them, or should I go directly to the pump?

Thanks.

 

[motorbiking]

what size pipe do you have from the hot water tank to the pump? If its 15mm you probably wont get much benefit upgrading the output to 22mm. If there is no reason to upgrade to 22mm you might find it easier to go copper to poly via the appropriate connector and back again. Or learn to solder or even use compression fittings on the copper pipe if you can't.

You don't so why you are doing this - and that will help

 

[just pumps]

Some pumps require 15mm others 22mm so do whatever the MI`s say.

 

[jtheobald]

what size pipe do you have from the hot water tank to the pump? If its 15mm you probably wont get much benefit upgrading the output to 22mm. If there is no reason to upgrade to 22mm you might find it easier to go copper to poly via the appropriate connector and back again. Or learn to solder or even use compression fittings on the copper pipe if you can't.

You don't so why you are doing this - and that will help

Thanks for your reply. It's 22mm from the tank to the pump. Then a length of 22 to the attic and from there the plumber reduced the bore to 15mm for some reason. The problem is the flow is strong enough to active the reed valve on the pump. By putting 22mm in I was hoping the flow increases and sorts out this issue.

 

[just pumps]

So somebody spends ages designing the pump for maximum performance then a weekend plumber decides he knows better eh!

Already said it once, What does the manufactures instructions of the pump say the pipe size`s should be?

 

[dilalio]

And why can't you use hep?

 

[motorbiking]

What fittings does the shower take - they are probably going to be 15mm - in which case upgrading the 15mm to 22mm might not make much difference. Does the pump serve anything else?

Is there an option to run the pipe under the floorboard and avoid going up to the attic and down again?

 

[just pumps]

Won't make any difference to the output

 

[motorbiking]

The issue is triggering the pump when the shower is turned on - or that's what I understood it to be. Its possible that air is getting in. I wonder if the tank is fitted with the correct flange, given how close the pump is to the tank.

Is the pump a variable speed pump? Might be worth turning it down.

 

[just pumps]

Post #4 said the flow is strong enough though, I`ve got other ideas as to what the problem could be myself but until the OP says more about why they are asking the Q I`m keeping mum. It would be helpful to know if this is a new install or even if a replacement pump or shower has just been fitted and the problem has just surfaced.

 

[maltaron]

Interesting that some Stewart Turner pump instructions state that 22mm should be used but supply 15mm flexibles for the pump.

 

[just pumps]

Both inlet & outlet?

 

[maltaron]

Yep, both inlet and outlet - 22mm tap connector to pump and 15mm push fit t'other end

 

[just pumps]

Well all I can say is always follow the manufactures instructions on both the pump and the shower and you wont screw any warranties.

 

[dilalio]

Yep, both inlet and outlet - 22mm tap connector to pump and 15mm push fit t'other end

And it's also annoying that only the inlet hoses have built-in isolators