Flow problem to shower.

[Darren Angel]

I have a thermostatic mixer shower with a salamander 2 bar twin pump connected. When i first turn on the shower the flow is really poor, by holding the handheld shower attachment as low as I can, the pump eventually kicks in and I can divert the water to the fixed head and shower as normal.
When i've finished showering and turn the water off it sounds like water is flowing back through the pipes, presumably to the cwsc and hot water cylinder.
Would fitting non return valves solve this issue and if so which ones should I get.
Thanks in advance.

 

[Darren Angel]

I should probably add, have changed the valve that controls the flow, I can't adjust the temp though so am guessing the thermostatic mixer valve also needs replacing, would a faulty one of these cause water to back flow?

 

[rpm]

Only if the shower is higher than the water feeds it might occur.

 

[Darren Angel]

Only if the shower is higher than the water feeds it might occur.

The fixed shower head is higher that the top of the cylinder, that must be the case in lots of situations. The cwsc is raised by about 1metre in the loft.

 

[Chalked]

You need a negative head pump.

 

[Darren Angel]

You need a negative head pump.

I have had this set up for about 8 years, with no problems. I replaced the pump a while ago and moved it from the loft to the base of the cylinder. Its strange it worked better in the loft than the recomended place. I am convinced its a pipe(water flow) issue or a problem with the shower itself, just can't narrow down excacly what the issue is.

 

[Chalked]

Your shower head is higher, than the tank that feed it.
It was lucky to work last time.

 

[Darren Angel]

Your shower head is higher, than the tank that feed it.
It was lucky to work last time.

My cwsc is about 2metres above the height of the shower head.

 

[rpm]

I have had this set up for about 8 years, with no problems. I replaced the pump a while ago and moved it from the loft to the base of the cylinder. Its strange it worked better in the loft than the recomended place. I am convinced its a pipe(water flow) issue or a problem with the shower itself, just can't narrow down excacly what the issue is.

Whatever is going on water cannot flow up hill on it`s own accord, pumped or a syphon effect yes and I cannot see it being a shower problem from here.

 

[Darren Angel]

Thank you for all the replies. I think its time to call in the pro's. I'm all out of logical ideas now.

 

[jacob BRISTOL heating]

Hi Darren,
So for double impeller pump
Pump inlet H&C water 22mm
Pump outlet H&C water 15mm
If pump has been installed next to HW cylinder make sure it has anti gravity loop if directly from draw off point or s flange
And you will need Anti gravity head pump

 

[Karl]

With salamander pumps aslong as the shower head is at least 600mm from bottom of cwsc then a positive head pump should be fine but then also if your hot draw off is less than 2 litres per minute then you need a negative head pump also is your pump on the hot side connected to a secondary hot tapping or a surrey flange?

 

[Darren Angel]

With salamander pumps aslong as the shower head is at least 600mm from bottom of cwsc then a positive head pump should be fine but then also if your hot draw off is less than 2 litres per minute then you need a negative head pump also is your pump on the hot side connected to a secondary hot tapping or a surrey flange?[/QUOTe

 

[Darren Angel]

I have a surrey flange. I think it is connected up wrong though, the pump is fed from the top and hot water to the rest of the house is from the side. This has been connected like this since my bathroon installer fitted our en-suite 8 years ago. The pump used to be in the loft and when I replaced the pump I moved it to the base of the cylinder. Is this what is causing my problems, do you think that just reversing these connections will solve my issues. Thank you for your advice.

 

[ShaunCorbs]

warix flange

 

[Darren Angel]

warix flange

Not sure what the difference is between a warix and surrey flange

 

[ShaunCorbs]

Not sure what the difference is between a warix and surrey flange

top port is the pump on warix

 

[Darren Angel]

top port is the pump on warix

Is it possible to identify the difference whilst in situ. flange was fitted 8 years ago by a plumber but I can't be sure which one he fitted.

 

[ShaunCorbs]

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