Shower Flow rate All aspects of plumbing questions and answers, help, tips and information

[gony]

Hi,

We have recently moved into a new house and the flow rate on the shower is pretty poor. It is rated at 8.5Kw and I was considering upgrading it to a higher wattage shower in the hope that I get a better flow. Before doing that I was looking for advice on how to test the rate of the feed to the existing shower to ensure that there is not a problem there. The flow of water to the cold taps in the house is very powerful so I was hoping that the flow from the shower is restricted by the low watage of the elements.

Cheers,

[htg engineer]

Is the shower definately fed from the mains or tank fed ?


htg

[rosebery]

As Htg suggests as an electric shower it should be fed from mains and if the rest of your house has good pressure that implies there is nothing wrng with your pressure.

Pressure and flow rate are NOT the same and I suspect yours is a flow rate problem. Its either a blockage in the pipework or the poor old thing is just scaled up to the "n" th degree and flow through it is substantially reduced. You could try replacing the heater can or replace the whole unit.

Whatever you do, however, you MUST NOT just willy nilly replace it with a higher power unit. The cable which supplies it MUST be appropriately rated for the rating of the shower and if you are in any doubt you and still want to use a higher power unit you MUST consult an electrican first.

Replacing it with an equivalent power shower should be OK though.

One final thought - Are you sure its not just the shower head which is scaled up? Have you tried removing it and seeing what the flow rate is like coming out of the end of the hose without the head in place? If thats equivalent to that from the taps the just descale your head.

Cheers

[gony]

Thanks for the replies.

Will check flow rate from hose - ta.

I have just been trying to untangle the mess of pipes up the attic. it looks like the taps and the shower are feed from the tank but I need to do some investigation to be sure. If it is fed from tank and the tap flow rate is good, if cabling fuses etc can accomodate it and there is no blockage then would upgrading to a 9.kw shower make much of a difference?

[gony]

Thanks for the replies.

Will check flow rate from hose - ta.

I have just been trying to untangle the mess of pipes up the attic. it looks like the taps and the shower are feed from the tank but I need to do some investigation to be sure. If it is fed from tank and the tap flow rate is good, if cabling fuses etc can accomodate it and there is no blockage then would upgrading to a 9.kw shower make much of a difference?

[gony]

I have determined that the shower is mains fed, from shower head flow rate is 3.75 litres per min. Tap flow rate is approx 1 liter/sec.

Wattage of this very old shower is 7.2kW.
Shower circuit is fitted with an MCB (hager MT140) rated for 40 amps.

The cable is stamped with "Pirelli General England 300/500V Basec" - how can I determine cable size? I want it to be 10mm so that I can fit 9.5Kw shower?

Thanks in advance

[rosebery]

You are not swapping like for like so you will need an electrician. You cannot avoid the old Part P and 17th Edition I'm afraid now.

3.75 litres per minute? - Did you really mean that and are you quite sure theres mains behind it in that case?

Cheers

[gony]

I am sure about the rate - I take it that is much slower than you would expect from an electric shower of that rating?

I am pretty sure about it being mains fed. I could turn of the mains supply and see if shower stops working to determine if its mains or tank fed? What kind of rate would you expect from a 7.5Kw shower _ if its much more than I am stating maybe the shower is at fault in which case I could try like for liek and avoid having to call out an electrician?