Unvented Cylinder, thickness of pipe

[izrr]

Hello

My plumber has recently installed a Worcester boiler and an Ariston unvented cylinder, 210ltr. I am also having a loft conversion.

The pipe coming from my water meter on the pavement is the copper 15mm pipe. Inside my property on the ground floor under stairs cupboard; my plumber changed the pipe from 15mm to 22mm. This runs up above to my bathroom where my cylinder sits, the rest of the pipes are 15mm. From my bathroom, the 22mm runs straight up to just before the loft conversion. The cupboard where the cylinder rest is located beneath the top end of the stairs leading to the loft conversion. The 22mm pipes go up straight but my plumber changed them to 15mm pipe across beneath the top end of the stairs and into the shower room in the loft conversion. All the pipes are 15mm in the loft conversion.

My water pressure is 3 bar in the garden. The pressure in the loft shower room in 2.5 bar but when the basin mixer is opened, the pressure reduces/drops.

The flow of the water reduces in the loft when the water is opened in the first floor bathroom. I have been told that my flow of hot water is greater than my cold water.

I was told that once the unvented cylinder goes in, I will be able to use the water/showers at the same time with no flow reduction of water.

Now my plumber tells me that this problem is due to the fact that I have a 15mm copper pipe coming into the property and I need to change it to 28mm pipe, which is another expense.

I would appreciate any help in this matter.

My question is:

Is it because my plumber did not carry the 22mm pipe into the loft shower room thats causing this problem?

Is it true that I need to change the pipe in my driveway in order to get the flow?

Is there something else we need to do to get the same flow of water everywhere?

Thanks

 

[wnjswozo]

new main into house i,m afraid to say

 

[moony]

as above - your plumber has done more than some would of - if there was 15mm coming into house a lot of plumbers would of run 15mm to the cylinder - at least he upgraded it to 22mm a bit pointless imo as its only 15mm coming in - but at least he thought of it in case you did upgrade the mains.

if im installing unvented system i always check incoming mains and advise as necessary.

 

[Blackcatgas]

a 100litre accumulator will fix this nicely, without having to change the incoming main.

 

[moony]

how big are they though?

 

[izrr]

New mains then...

Is it guaranteed to increase the flow on all 3 floors?

I am thinking of having a garden extension in the future with a wet room on the ground floor, so all in all, 3 shower/bathrooms.

Thanks.

 

[Steve001]

the 15mm pipe will be attached to lead or something else, I can't see it coming from the mains in copper? The other thing is, what is your flow rate? could still be good even with what you've got, and what's it like with other taps running. how many litres fall into a bucket in a minute, 22 litres is usually plenty, how much does your system need?

And blackcatgas, accumulators - any good? Are they a good answer to all flow rate problems? never fitted em

 

[ferret]

here we go again! check out previous posts on megaflo pipesizing and you will find the answer...

 

[Scottley]

I had a 15mm copper feed to my house and put in a 250lt megalflo. The pressure was fine unitl like you i opened another tap. I replaced the incoming main to 25mm and now its fine. It reduces down at the stopcock to 22mm all the way to the megaflow (20mts)

System is perfect and pressure excellent. Go or the mains change if you can.

 

[stevew451]

both flow rate and pressure need to be checked before instillation

with any pipework be it water gas steam the more you add the less you get out of the source

 

[izrr]

Thanks to all.

Changing of the main pipe is the answer then....