Mixer shower - low hot pressure.

[phillsmit3]

Hi I have a problem with my shower.

The hot is fed from a cylinder and the cold is mains.

We rarely use this shower as we use our other bathroom.
We had a problem in the other bathroom and had to drain the ccylinder.

While we also had to order some parts so we refilled the cylinder and used our other bathroom.

The shower in the other bathroom is not working properly now though.
I'm not sure if it could be due to the other problem or if we have only now noticed it as we haven't used it for a few months.

Basically we have to put the shower on full blast hot for it only to be warm
It is also very weak pressure.
We didn't have the problem before and the bath taps, shower on the taps or sink have this problem

Could this be an air lock or is it more likely to be a problem in the mixing valve?
The cold water is coming through very powerful.
The hot pipe before it gets to the mixer is boiling hot.

Does anyone have an idea what is causing this.

 

[phillsmit3]

Picture

 

[MrMeek]

its not balanced, cold is mains and hot is gravity, you need to balance it by installing a cwsc so the hot and cold is both gravity fed, then if pressure/flow is still low install a pump, basically its installed wrong mate

 

[phillsmit3]

We have a cwsc but mains has been used for some reason.
The funny thing is that it has worked perfectly previously and also the shower attachment to the bath taps is plumbed up the same way and works perfectly.

Could it not be something like an airlock in the hot water side or the value in the shower mixer unit itself.

It seems funny the pipe is boiling hot just before the mixer but when the shower is on full blast hot it only comes out with low pressure and is luke warm.

I was hoping it could be the value in the shower mixer which is only letting a trickle of hot water through and mixing it with some cold.

Could this be a possibility?

 

[phillsmit3]

p.s. The pressure on the hot tap and hot on the bath tap shower attachment is excellent.

 

[jam1979]

needs re pipeing