Continuous Airlocks in newly fitted Pump Powered Shower

[rhbmcse]

Long Story Short...

Bought new house - ensuite shower doesn't work.
Not surprising - ensuite shower head is above hot water tank height (both on 1st floor).
Plumber bought in to fit pump - fitted into loft - new hole put into hot water tank to feed it.
Amazing pressure 1st shower.
2nd shower pressure useless.
Plumber called in again - airlock.
Plumber in loft - airlock shifted - shower amazing.
3rd shower pressure gone again.
I read the installation manual - "Pump should never be fitted above the height of the hot water cylinder as requires gravity pressure - fitting in this way may cause airlocks"...
Plumber called back in again to relocate after quoting instruction manual.
Pump relocated by plumber next to hot water tank in airing cupboard as recommended in the instruction manual.
1st shower pressure amazing.
2nd shower same problem and continuing to this day.
The shower keeps airlocking. This can be cured by shutting the pump off by switching the shower off, and turning back on again (usually harshly to the fully hot position) - after a few coughs and splutters the shower is back to full power again but I shouldn't be having these problems every time I shower.
After reading the manual again it says that 90 deg bends should never be used which they have been.
Also it states that if the shower head is above the height of the cylinder (which it is) a negative head kit should be used.
As I understand it this is merely to kick the pump in if gravity pressure is not adequate to do so, but we do not have a problem with the pump kicking in, just airlocking.
Any advice gladly appreciated.
I don't want to call the same plumber in as I have no confidence any more.

 

[seco services]

it don't matter if the shower head is above the hw cylinder which 9/10 times it is, its how much distance between the cws tank in loft and shower head useally has to be 600mm or greater any less will put you in a neg position.

have you any pics of the piping to the pump in airing cupboard ?

 

[rhbmcse]

...well I havent taken any but I certainly can do if it helps.
Anything specific that you were looking for so I can make sure I get it in the shot?

 

[rhbmcse]

I have just measured the shower head distance to the ceiling.
The shower head itself is 260mm from the ceiling.
The pipe feeding the shower head coming out from the wall horizontally is 130mm from the ceiling so even though the cold water tank is raised onto a platform we would be pushing it to obtain 600mm.
If it is there, it's only just but I cant accurately measure this.

 

[ChrisR]

Where and how is the hot supply, cylinder, to shower, connected?

ANy chance of mioving the pump to by the base of the cylinder?

 

[seco services]

but thats not the cause of the air.
that useally only restricts the pump starting when shower turned on.

need some pics of the pipework in the airing cupboard

 

[rhbmcse]

The pump is already by the base of the hot water cylinder - I had it relocated by the plumber as per my original thread.
Taking photos now - will post shortly.

 

[rhbmcse]

OK Here is the pump located at the base of the hot water cylinder, along with a shot of the newly fitted pipework into the cylinder solely feeding the hot water supply to the shower pump.

Sorry the pictures are on their side!

The cold water feed comes directly from the loft

Untitled

• rhbmcse
• 18 Jun 2008
• 1

Untitled

• rhbmcse
• 18 Jun 2008
• 1

 

[seco services]

just looking at the top of the cylinder pic.
no wonder your drawing air in that a right old bodge.

 

[rhbmcse]

...well originally that went UP and into the loft...

 

[seco services]

its no good like that an air that in the cylinder will rise up the side of cylinder and take the first exit out which is your shower and cause air don't go down hill will get trapped in the top of the copper section.

 

[seco services]

i would fit a new flange in the tank.
surrey flange
essex flange
they are designed for showers etc and designed not to draw air in.

 

[rhbmcse]

I hear what you're saying.
Do you have any suggestions as to how to remedy this situation - in your professional opinion?

 

[rhbmcse]

In the same location or would the existing one need to be capped and a new hole drilled for the new flange?

 

[seco services]

just cut the pipe on that one leaving an inch and put a cap end on.

a surrey flange gos in the top centre where your other pipe comes out it just converts that to two pipes instead of one.

essex flange gos in the side of the tank.

a surrey flange will work fine with your set up and can be converted in no time.

this is a surrey flange when fitted.

http://www.bathroomexpress.co.uk/images/techflow_turbo_installation_manual_fig3.jpg