Shower Pressure question

[Boxerman]

Just fitted a salamander CT75 pump to a new shower, one of those antique types with an 8" rose and separate hand held flexi head) I have 400 lts water storage in the loft with approx. 600mm head over the shower rose.

When I turn the shower on nothing happens however if I lower the separate flexi shower head to waist level the water starts to flow and the shower pump kicks in, I can then switch over from the flexi head to the 8" rose with no problems. Once off, I have to re-do this process.

I did wonder if the fact that I routed the plastic pipe from the pump to the shower head above the cold tank in one long length (to avoid joints and minimise sharp bends) might be causing this or is it more likely that I just don't have quite enough height on the cold water tanks.

 

[seco services]

bring the pipe down along the rafters below the tank.
you need to get a good 1 ltr/min gravity per side hot/cold to activate the pump flow switchs.
and fit manual bleed valves in the pipes at the highest point to bleed the pipes of air.
and your hot should have an anti gravity loop fitted after cylinder and before pump.

 

[dal5band]

You need a bit of flow to trip the flow switch(s) located somewhere in the pump - you are obviously not getting enough flow to start the process. Just try to improve things to get the flow up a bit under gravity to trip the switch.

- Check there are no restricters in the input connections to the shower (washers with small holes to restrict the flow). Some showers come with these fitted.
- Check any isolating valves are fully open. You may need to install full bore isolating valves if the ones you have have small holes.
- Check there are no high points where a small amount of air could be trapped which may slow the flow under gravity.
- Basically you should get some flow under gravity to your top shower head - check there are no little obstructions etc in the pipe up to the shower head.

 

[Boxerman]

I thought I only needed an anti gravity loop on a negative head application.

Fitted full bore valves to hot and cold supply, I guess I'll have to see if I can 'bend' the plastic pipe tighter to run along the ceiling joists, or perhaps as a final option lift the tanks.

Would a negative head pump be a better option?

 

[Boxerman]

........and can heat be applied to the plastic speedfit pipe to help it form a tighter bend, hoping to avaoid joints and therefore potential problems/leaks

 

[tonybhoy]

No don't even think about applying heat.

 

[Boxerman]

OK so I've re-routed the pipework along the joists and still can't get enough flow to get the pump working even if I drop the shower hose down to bath height.

So would the advice be to change the pump to a negative head one @ £300 + or to raise the cold water tanks which will take time and how much do I need to raise them by?

 

[seco services]

how have you connected your hot supply to the cylinder ?
where is your pump in loft or next to cylinder ?
how long are the pipe runs from the pump to shower ?
and i take it you have run 15mm pipe not 22mm.

 

[Boxerman]

Hot supply to cylinder is via 22mm copper from cold tank in loft approx 10 ft above clinder base.

Separate cold tank supply in 22mm direct to pump with full bore 22mm lever valve.

Supply to pump from Warix Flange and withfull bore lever valve.

Pump is 6" above base of hot cylinder.

Pipe run to shower is approx. 35 feet in 15mm Poly pipe with no joints other than at each end i.e shower and pump

 

[seco services]

35ft in 15mm is no good, to far should of kep it in 22mm.
you need a least 1 lt/min flow from each side on gravity to operate the flow switchs in a ct pump.

 

[Boxerman]

Re-routing in 22mm will be very difficult (Salamader had said 15mm was OK).

So is it a new pump or raise the tank?

 

[seco services]

Re-routing in 22mm will be very difficult (Salamader had said 15mm was OK).

So is it a new pump or raise the tank?

salamander has said it was ok

it can't be it's not working.


what flow in litres are you getting from each on gravity ?


yes maybe easyer to raise the tank

 

[Boxerman]

I'm barely getting any flow through the shower head, certainly not the 1ltr/min to trigger the pump.

I know it's not an easy answer but how much do you think i'd need to raise the tank by as I'm thinking that perhaps I'll have to bite the bullet and by an ESP negative head pump to save the hassle if I'm going to have to raise it bt too much.

 

[seco services]

about 600mm

 

[Boxerman]

oky doky, will give it a go and report back.

Thanks for your help Seco