Is a S flange out of the HWC really necessary ?

[realstokebloke]

Most shower manufacturers actually recommend tee ing downwards from the horizontal outlet with a pumped system. Check out aqualisa website for diagram

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Cheers KJ:

yes had a butchers at the Aqualiser site & the draw off the existing piepwork is most preferred & the flange is least (very odd?):

[DLMURL]http://www.aqualisa.co.uk/upload/INSTALLATION%20GUIDES/Install_Mach250_340.pdf[/DLMURL]

But, my draw off pipe (out of the HWC at the top) is vertical, not angled 'up' to the HW pipe network at the moment anyway - so would have to change that too &, at the end of the day, i have a Salamander and am pretty sure they do recommend a flange (i think they call a Surrey - the one at the top - a "S" flange).

They do:

http://salamanderpumps.co.uk/WebResources/Documents/Installation_Guidelines_Oct2011_Issue14.pdf

(So it's odd they & Aqualiser totally disagree on the same basic issue that the restriction of the flange outweighs the benefit of airation?)

So i take the hint that it's best to fit one or the other type of flange as barron bathrooms says - it then complies with the spec & warranty.

But...it will take a change of the pipework at the top - so i will post a pic of the existing to follow for a hint on what that entails if anyone can help / advise.

Thanks.

 

[Best]

Warix & Surrey flanges are very similar to each other, but if you have existing male bend on top of cylinder, then Warix is direct replacement, as the hot to all other supplies is from the side of a Warix & air free supply out of top for pump. Surrey flange is the opposite.
I personally wouldn't use Essex flanges even if I got them for free, as though they do give full flow, they are prone to leak due to heat on those rubber washers, destroying them. A new cylinder with a tapping near the top of side is best, or else Warix/Surrey flange. IMO.

 

[Howsie]

Do what every you're comfortable with and can afford now and in the future. Follow the MI and the pump manufacture will honor the guarantee. Don't and they won't. Bubbles are bad for a pump impeller.

Most of the pumps I've replaced have been tee'd into the hot feed off the top of the cylinder so make of that what you will.

Bubbles are bad for a pump impeller.

 

[kay-jay]

page 6 here [DLMURL]http://www.aqualisa.co.uk/upload/INSTALLATION%20GUIDES/Install_Mach250_340.pdf[/DLMURL] shows most preferred to least preferred options for connecting hot to pump. from aqualisa, and based on rigorous testing. note that essex/surrey flanges are not on list.

by teeing DOWNWARDS ​ air free supply is guaranteed as air does not travel downwards.

it all seems strange that shower mi's and pump mi's disagree on this though. follow one and ivalidate warranty on the other....

 

[kay-jay]

if you think about it teeing downwards from the hot supply it works on the same principle as a flange.

a flange has a dip tube which means that water is drawn from below the surface which ensures air free supply because any air above the diptube inlet will not enter supply because air will not travel downwards in water..........

 

[kay-jay]

in fact i just found this....

from stuart turner. the info here http://www.stuart-turner.co.uk/media/4336-Showermate-Standard-Single-and-Twin.pdf is exactly the same as that on the aqualisa website look at the wording and the diagrams). page 6 again shows preferred feeds and happily reccomends feed from hot supply without flanges.

 

[kay-jay]

therefore it follows that only the cheaper end of pump market is concerned about its impeller build and operational quality............

or perhaps they manufacture flanges......

 

[Howsie]

Air does travel downwards with water; small bubbles will follow the flow.

 

[kay-jay]

Obviously not to any degree that concerns Stuart turner just salamander., there may be others though. But two of the best makes of shower and pump respectively actually recommend teeing into supply rather than using a flange pg6 in the above links.

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[Howsie]

They probably tolerate the bubbles better than most.

I'm sure part of the reason that the 'tee' is in the MI's is to appear easy to install to the lay person.