Shower pressure

[jtheobald]

Hi,

I wonder if somebody can point me in the right direction please?

My mothers shower does not activate unless the head is dropped below her running bath taps. After that and turning off the bath taps everything is fine. The hot water is fed from a gravity system, with the tank on the floor above.

She has recently disnosed dementia/Alzeheimers so forgets how to use this work around, thus I want to come up with a permanent solution.

I have replaced the head, hose, mixer (low pressure) and piping behind the shower. I have not touched the mains pressure reducer, which is quite old.

I have thought about a pump on the down pipe beyond the isolation valve or the horizontal pipe, but concerned if it doesn't get a water supply it will burn out.

Could air be causing the issue?

I include an image which I hope helps. The bit you can't see are the pipes feeding the bath below. This is approx 40cm in length.

I would appreciate any advice please?

Many thanks

 

[jj4091]

Are you talking about a thermostaic mixer valve type shower or one fed from a mixer on the bath taps.

 

[jtheobald]

Are you talking about a thermostaic mixer valve type shower or one fed from a mixer on the bath taps.

Sorry, I missed that bit: thermostat mixer. I have replaced it with a low pressure mixer.

 

[denso13]

Should really be balanced supplies, one off gravity and one off the mains could be causing issues.

 

[jtheobald]

Should really be balanced supplies, one off gravity and one off the mains could be causing issues.

Thanks, I wondered that and the pressure to the property is good; although I know it's as good as what's throttled at the pressure reducer. I assume that if the hot is low pressure then the reducer is also turned down to low..

I don't know how old the pressure reducer is, but more than 20 years... do they need maintenance or to be replaced?

I'm wondering whether to replace the reducer and as I said earlier install a pump on the pipe.

 

[denso13]

Hot will be low pressure, the cold will still be mains pressure, even if reduced by the valve. They should either both be mains, or both gravity. This can cause issues like you are experiencing, some valves seem to be more temperamental than others.

 

[jtheobald]

Very helpful, thank you.

 

[jtheobald]

Thinking about it, like you do. If I fit a gauge to the reducer and find out the bar and match this to a booster on the hot pipe - should this technically work?

 

[denso13]

Maybe, bit of a punt though. What actual shower valve is it, you mentioned low pressure?

 

[jtheobald]

It's a Deva. The old one wasn't any better.

 

[jtheobald]

Hi, the latest.

I fitted a new isolation (full bore) valve as the old one had failed. Don't know where the rubber seal has gone!

I also fitted a guage to the pressure reducer. It shows approx. 3.75 BAR. I tried to adjust the valve but it showed no difference. Interestingly, there wasnt a filter in the valve..

Not sure where to go from here - apart from getting a professional!

Would you recommend replacing the reducer valve as it looks pretty old.

Thanks in advance.

John.

 

[denso13]

Would you recommend replacing the reducer valve as it looks pretty old.

Depends how much you want to spend on something that may not work. The pipework is the issue.