Increasing Shower Flow

[carder1]

A few years back we added an extension to the house including a shower which has a very poor flow. Thought of installing a pump but since the toilet, sink and utility room are all fed from the same 2 15mm hot and cold pipes, this cannot be done. Moreover, we have absolutely no access to install new piping to each installation.

The cold water is gravity fed from the tank in the loft and the hot from the tank in the airing cupboard. In both cases 15mm piping has been used. It would be possible to replace both 15mm pipes with a length of 22mm from the tanks, (1m to the hot and approx 3m to the cold) but I really don’t know if this would increase the flow to the shower and of course to the other facilities. What do members think?

[carder1]

Question rephrase. If I replace short lengths of 15mm pipes at the tanks with 22mm piping will this increase the flow of the shower?

[carder1]

Out in the sticks with the nearest plumber some 40 miles away and much too costly for such a small job, had I got a positive reply, I would have attempted the job myself. However, with no replies one way or the other, I’m at a bit of a loss. Is my question too naive?

[wine~o]

Question rephrase. If I replace short lengths of 15mm pipes at the tanks with 22mm piping will this increase the flow of the shower?

No.

But you could fit a pump inline (if there is room) you may need to change the loo valve to one that is more suited to higher pressure (they normally come with 2 inserts, one for high one for low)

[carder1]

No. But you could fit a pump inline (if there is room) you may need to change the loo valve to one that is more suited to higher pressure (they normally come with 2 inserts, one for high one for low)

Absolutely no room to fit an online pump! However, I already have a pump in the airing cupboard feeding another shower and could easily split the h and c feeds to additionally supply the various units in the extension. But again, I’m maybe being too naive.

[Someone-Else]

I would say that changing just a small length of pipe would be pointless.

As for adding a pump, its not as easy it it first sounds. You have to take into consideration flow rate, pressure and volume and storage tank size.

If you pump too much / too fast you can get cavitation

Bigger pipes for the whole run and or raising the cold water tanks will help.

[wine~o]

No. But you could fit a pump inline (if there is room) you may need to change the loo valve to one that is more suited to higher pressure (they normally come with 2 inserts, one for high one for low)

Absolutely no room to fit an online pump! However, I already have a pump in the airing cupboard feeding another shower and could easily split the h and c feeds to additionally supply the various units in the extension. But again, I’m maybe being too naive.

The only issue I can see with that is multiple users, one using a pumped supply in one room and some-one else in another.

As per S-else, size of storage tank in the loft ? how is the current pump connected ?

[carder1]

Current pump connection:
1st photo shows the grey hot feed to extension including kitchen, utility room and shower room .

2nd photo shows hot feed from tank to pump in the foreground and at the rear, cold feed to extension.

3rd photo shows cold feed pipe to pump from tank in loft on the left and on the right, the 2 pipes feeding a shower in the bathroom.

4th the pump

Tank approx : 60 (h) x 60 (d) x 120 (w) cms

[carder1]

Given that I might have to swap over the loo valve, it would be a very simple task for me to swap over the pipes feeding the bathroom shower with those feeding the shower in the extension. With the pipe feeding the latter being 15mm, might I expect any other problems other than the loo valve as wine~o pointed out?

[darrenba]

What sort of shower is it? Some showers work better with lower pressure than others. All you might need to do is replace the shower with one which deals with low pressure better.

For example

this one delivers 6Ltr/min at 0.1bar (decent)
https://www.screwfix.com/p/aqualisa-aqu ... ower/22227

Compared to

this which delivers 1.4Ltr/min at 0.2bar (crap)
https://www.screwfix.com/p/cooke-and-le ... ower/2635t

[carder1]

It’s a 15 year old Mira Eco.