Vented to Unvented, shower pressure problems

[allesclar]

Hello everyone,

New here but this is driving me mad.

We had a vented gravity fed water system and the shower was fed via a mains powered water pump and storage water tank, with inlets for both hot and cold fed to a mixer in the bathroom.

In order to free up space in the loft and give better hot pressure throughout the house I enquired about an unvented pressurised cylinder system (and a few other improvements).

I was assured that the pressure of the shower would not go down with the removal of the shower pump as the incoming pressure at our house is really good.

The new system is in and the new cylinder is capable of 3 bar pressure and the pressure out of all the taps has increased signifcantly.

However the pressure of the shower is probably half of what it used to be and this is something i am not happy about.

15mm piping is used from the incoming main to the cylinder, then 22mm is used upto the attic and a reducer is used with 15mm piping all the way to the shower.

It has been suggested to use an accumulator but that will set us back around £700. (for the sake of shower pressure this is an aweful amount of money)

What options do i have as i feel abit annoyed after spending alot of money with the promise of keeping the power shower pressure but not having it. Is there anything else that can be done or something i have potentially missed?

I have read reviews online about people getting rid of their shower pumps and switching to pressurised systems and keeping the shower pressure.

Cheers everyone

 

[galaxy_plumbing]

change to normal shower, not power shower, it should work unless is something dodgy with the install.

 

[Meady]

The 15mm cold mains to the cylinder doesn't sound to good though

 

[townfanjon]

the most important thing here is the pressure AND flow going to the cylinder, but assuming your installer is qualified to work on unvented he should have checked it before commencing the work.
Have you any idea what they are, you are looking for ideally above 3 bar (but you would probably get away with 2.5 ish, but your flow should be around 20 /25 litres a minute.

 

[Plumbstar Tom]

check the shower filters, when they made the changes some small debris could have gotten in and blocked the pipe work

 

[allesclar]

Thanks for the replies everyone.

I have had another plumber come and have a look.
Its 15mm piping up to the cylinder as suspected and he measured a flow rate of 7litres and pressure of 2bar at the incoming main, off a 15mm section of pipe.

This is really low but have been told it could be the stopcock on the incoming main.

His proposal is that replacing the stopcock and running a dedicated 22mm pipe to the cylinder could help.

But the incoming pressure and flow isn't very good.

I have taken the head off the shower and cleaned it out and no improvement.


I am annoyed that our previous plumber, the installer thought the low and pressure would be OK.

Do you guys think its worth doing the proposed work. Currently the piping to the cylinder in 15mm does seem to go half way round the house.

Cheers

 

[Ermintrude]

Remove the pipe from the stop tap fit two ISo valves on a tee. Connect a pressure gauge to one and a hose to the other run water and measure flow rate and record pressure. If at the stop tap you only have 17lpm and 1.5 bar no point but 20lpm and 2bar yes do it. But keep the 15 to the cylinder and use it to feed the rest of the house as a balanced cold .

 

[allesclar]

Thanks for the reply.

Am i right in thinking to measure the pressure while another tap is affectively on?

When he took the pressure it was only off one end. He measured 2bar and 7ltrs a min, but this was out of a kitchen tap which is right just off the main incoming, but has those flexi hoses so i guess that coudl really hamper the flow rate?

What do you mean by the last bit, basically keep it as it is?

Cheers

 

[allesclar]

Cheers for the replies everyone.

Out of curiosity, aside from the invoice for the work and parts, what other documents should i have been given?

Surely a warranty on the pressure tank and test certificates etc for the new pressurised system?

Cheers

 

[Whyme]

Have a look at the manufacturers instruction for the cylinder, at the back there should be a tick type list (benchmark) that he should have filled out and signed..The ones i fit do.