Changing shower take off locations to improve flow

[djheath]

My shower flow rate is terrible and regularly gets air locked. I'm thinking this is a combination of factors namely; 1. The hot water take off from the cylinder is from the vent pipe and well above the cylinder T. 2. The pipes go up into the loft via quite a few bends and are only just below the cold water tank. The pitch of the roof is quite low and the cold water tank is only just above the loft floor, so pressure isn't great.

Here is a diagram to illustrate the setup:



To improve flow rate to the shower, would it be better to change the hot water take off point to somewhere just above the cylinder using something like a surrey flange rather than high up on the vent pipe?
Would changing the cold water take off for the shower be better if it was taken off the cold water tank output, rather than the mains riser, to equal the pressure between the two?

Or would it be better to do both the above and fit a pump?

 

[Madrab]

Or would it be better to do both the above and fit a pump?

^^^^ This ... without a doubt ^^^^

 

[denso13]

You may improve the flow rate a bit but will always be constrained by the height of the storage cistern. Agree with Rob above.

 

[djheath]

Thanks for the replies. So next question:
With the bottom of the cold water tank being located about 10 cms off the top of the loft joists, and the shower pipes running over the loft joists to get to the bathroom (about 6-7 metres total length each), does this mean I have a negative head and would need a negative head pump? Can this pump be located in the loft above the hot water cylinder, of is it preferential to site the pump as close to the cylinder as pssible?

 

[ETAF]

i had a bathroom redone last year, and in a bungalow with reduced pressure to the shower head on the bath,
But it gives a good shower
1) I made sure the 22mm went all the way from the TANK to the hotwater tap in bathroom/shower
2) The taps/shower are low pressure fittings, also tried a few different shower heads
3) I changed the shower hose to a bigger bore 11mm from screwfix https://www.screwfix.com/p/croydex-shower-hose-chrome-11mm-x-1-5m/328fh
4) Added a pressure reduce, from screwfix , to the cold tap feed on bath https://www.screwfix.com/p/reliance-valves-predator-pressure-reducing-valve-15-x-15mm/914hr

and result is an excellent shower, with the head just a few feet from the hotwater tank takeoff

Was thinking of going the PUMP route, looked into quite a few types, but the hotwater tank was not big enough for a PUMP, and fitting a PUMP is notifiable to the water Authority at least it is in my area West Sussex

 

[Madrab]

fitting a PUMP is notifiable to the water Authority at least it is in my area West Sussex

Only if you are pumping the mains then for sure, in some areas, it may be notifiable. Not sure about pumping your own cold water storage cistern and hot water cylinder though. Unless they are are on a major drive to save water and have made it a bylaw.

 

[Madrab]

does this mean I have a negative head and would need a negative head pump?

No, but it is in what is termed as the dead zone and there may not be enough flow to activate the pump. In those cases a universal pump would be advisable.
Ideal site is on the floor next to the cylinder.