Shower Pump Problem

[DPS]

Hi all, hope someone can help.
I have installed a Stuart Turner Monsoon 2 bar twin for my shower. Cold water feed from storage tank into pump and hat water direct from cylinder through an essex flange.
The shower is a Milan Triple Thermostatic Valve with Square Shower Head and Handset.
When i switch the shower off and use the handset it works fine. Once the handset is turned off and i want to switch the shower back on the shower does not work.
I then have to leave the shower on without water running through go to the airing cupboard (where the pump is installed) and open the drain-cock. The pump then kicks on and water runs through to the shower that was left on.
The same happens sometimes once i switch off the shower and want to turn it back on after 5sec then no water will come out. I then have to do the same as discribed above by opening the drain-cock for the water to run.
i hope someone can let me know what needs to be done for this to stop.

Many Thanks,
DPS

 

[chris watkins]

Are you sure it is a drain off you are opening, not an air vent ?

Does the pump just feed the shower?

Is it all piped in 15mm?

 

[Frog67]

several things you could check,,, is the shower head higher than the water tank? are the filters in the feed hoses clean? as Chris asked.. what size is it piped in? where in relation to the installation is the pump positioned?
Answers may help to diagnose the problem quicker

 

[DPS]

Hi Chris, Yes its the drain vent and the pump only feeds the shower and its all piped in 15mm.
After about 3min after I had a shower I can hear water running out of the shower head so that will also create some air in the pipes.

 

[DPS]

Hi Frog, the shower head sits below the water tank and everything is installed new so hopefulle clean yes.

 

[chris watkins]

The pump hot side is almost certainly suffering cavitation or drawing in air and then locking so there is no flow to bring the pump back on again, which is why you have to vent the draped air.

You need to follow the Manufacturers Instruction, when they say they have to be piped in 22mm and from an air free supply they do so for a reason.

Sorry DPS

http://www.stuart-turner.co.uk/medi...gle-and-Twin-ShowerPump-WholeHousePump-IG.pdf