Gravity shower - reduction in pressure

veryintrigued

SuzieSue wrote: »

We had a similar problem when our shower was replaced (very disappointing when you've paid all that money for a new shower and the result is worse than the old one).

We were going to get a pump, but I thought that I would try a different shower head and got this one:

Euphoria Mono Hand Showerhead:

http://www.amazon.co.uk/Grohe-27224-Euphoria-Hand-Shower/dp/B005OQ2RTM/ref=pd_sim_sbs_kh_1

It made such a difference that we didn' bother with a pump.

That might be an (cheap) option to try!

Thank you

veryintrigued

Plumbers_Shop_Lee wrote: »

the data sheet on that shower suggests at 0.5 bar pressure you will get 7.7 lpm which to be honest is pretty poor although as Keystone says the only way you'll increase that is to pump the supplies. just out of interest what is the distance from the base of the cold water storage tank to the head of the shower (this needs to be a minimum of 5m to attain 0.5bar). Bristan claim this to be suitable for all system types I really dont think it is, for example the Mira coda will operate at 0.1 bar which is far better suited to your system

Been to the loft and the cold water feed tank is around the 5M from the shower - the boiler (hot water feed) a little more (but on the same floor).

Interestingly looking at in progress in pictures (before plaster and mermaid board was applied) the hot and cold water feed pipes to the bottom of the shower valve. Am guessing this is normal?

veryintrigued

Mr_Ted wrote: »

:)In agreement with some of the above, as it would appear you do not have enough head(keep it clean) for required flow, and that a pump is the probable solution;)

I would also check if you have a dedicated cold feed to the shower from the CWS tank and that the hot feed is from a dedicated tapping from the cylinder also, if not it should have one for a pump so that you have equal supply head and flow for the pump to work on:)

I would also advise putting the gauze filters back in;)

I dont think the cold feed is dedicated (tough to tell in loft with lagging) and that pipes disappear under boards - so I guess this could be a factor. Similar story with hot feed.

southcoastrgi

the 5m isn't the distance away, it's the distance above the shower head (if it's a fixed head)

veryintrigued

southcoastrgi wrote: »

the 5m isn't the distance away, it's the distance above the shower head (if it's a fixed head)

I think you may be right - I'm the one thats crackers!!

keystone

veryintrigued wrote: »

Been to the loft and the cold water feed tank is around the 5M from the shower - the boiler (hot water feed) a little more (but on the same floor).

Horizontal separation is irelevant. It's vertical separation that counts. From your cold tank to the shower head is probably iro 6 feet vertical which will give you iro 0.25 bar. The fact that it might take a couple of horizontal runs in the middle doesn't alter the maths.

Interestingly looking at in progress in pictures (before plaster and mermaid board was applied) the hot and cold water feed pipes to the bottom of the shower valve. Am guessing this is normal?

Top of valve, bottom of valve, middle of valve doesn't make any difference practically.

Cheers

Edit; SC got there first!

keystone

veryintrigued wrote: »

I dont think the cold feed is dedicated (tough to tell in loft with lagging) and that pipes disappear under boards - so I guess this could be a factor. Similar story with hot feed.

The point here is that the supplies should be balanced - they should be at the same pressure. If you feed the cold to the shower from the maisn riser it will be at significantly higher pressure than the hot fed from the tank. So the cold will always overwhelm the hot almost wherever you set the shower control in those circumstances. Once you introduce a pump it's important that those supplies remain balanced. Its also important that if someone opens the hot tap in the kitchen or the cold tap in the bathroom that the shower is not starved because in those circumstances the person under the shower can either freeze or be boiled with a non thermostatic shower. So if you have a pump the system is piped such that the pump (and thus the shower) must be given independent supplies of both hot and cold from the cylinder and cold water storage cistern respectively. Its also good practice to do that with a gravity shower as well. So your system may or may not be piped in that way now.

In essence your installer has just banged the shower in and paid little heed to overall system configuration (which he should have done before quoting incidentally not finding out after the event) with the result that you are not satisfied.

You need to call him back IMO.

Cheers

diywhynot

veryintrigued wrote: »

See link above (its the same as any photo) - unless youre keen to see out mermaid board?

Photos of the installation, not just a stock photo of 'similar' valve.

You seem reluctant to contact your installer.