Can you identify this bath shower mixer problem?

[Nobbyone]

Hello,

I work as a as Domestic Electrician/Handyman. A customer who rents a property asked me how to operate her bath shower mixer as she could not ever get it to work as a shower. For the life of me I could not work it out. I took what I thought was the control valve off but still no water was directed to the shower outlet. There is no push or pull just an unscrew of the whole thing. Is it missing something? Am I missing something such as a loose screw in my noggin? I have attached some images of the whole thing and a close up of the valve area.

Can anybody enlighten me? If I am a complete doughnut then please let me know, nicely please

 

[Paulus]

Does thta knob between the hose nut and the tap body turn to open a valve?

 

[Rich8]

There might be a nrv in there that's jammed ?

 

[Nobbyone]

Hi Paulus,

I originally thought that by unscrewing the knob slowly it would allow water to pass to the hose, but it doesn't. The knob appears just to join the body and the hose together, no valve is visible.

It just screws off leaving a chrome pillar with a hole in its flat top that is sealed by a simple flat washer held loosely in the unscrewed knob part. With the knob removed completely, leaving just the mixer, there is no lever, hole for a rod, nothing, just the metal pillar.

With the knob completely removed and full water flow out of the cold tap not a drop leaves the pillar. It makes no sense at all.

Could the valve control be built in and controlled by a lever under the mixer?

 

[Nobbyone]

There are no moving visible parts, everything appears to be solid. So how is the flow switched? My bald spot is getting bigger.

 

[Plumbstar Tom]

does that part under the hose connection pull up or push down. it will be jammed after not being used for so long. Remove the hose and introduce a rubber mallet to it

 

[Nobbyone]

Ah Ah. It could be a pull up job Plumbstar Tom, but where has the water flow gone? Could it be a combination of a stuck NRV which has led to the previous tenants not using so it and now the control has completely seized up?

Can the internal NRV be un-jammed or will the whole mixer need replacing?

 

[Paulus]

As Tom says, I'm sure that knob must be the diverter in some way. Maybe the washer you describe is completely jammed due to the shower not being used for such a long time. Looking at the picture again, there is a gap under under the knob which would seem to suggest that it pushes down as Tom says.

I do seem to remember one in the past which diverted in this way.

 

[Nobbyone]

Thanks Paulus.

After looking at it again from memory it could be that the mixer might never have worked.

A combination cylinder is being used which is located just outside the bathroom in an airing cupboard.

The height difference between the top of the cold part of the cylinder and top of the bath is about a metre. I'm thinking that there might not be enough pressure to operate the valve to the shower hose.

Would a shower mixer work using this setup?

 

[Paulus]

Hi Nobbyone,

You are probably quite right, 1 metre = 0.1 bar pressure which is probably not enough. Assuming the cold water feed tank is tiny, a pump wouldn't be an option so the only way to provide a shower for your customer would be by fitting an electric one.

 

[Nobbyone]

Hi Nobbyone,

You are probably quite right, 1 metre = 0.1 bar pressure which is probably not enough. Assuming the cold water feed tank is tiny, a pump wouldn't be an option so the only way to provide a shower for your customer would be by fitting an electric one.

The feed tank is tiny and is located in a 3/4 (or is that 0.75 these days) sized cupboard. So it's bad news for the tenant. Thanks for all your help.