Low water pressure at bath and shower All aspects of plumbing questions and answers, help, tips and information

[bavyboy]

I have just fitted a mixer tap on the bath come shower and the flow rate has dropped.Would raising my cold water tank in the loft remedy this,if so how much would I need to raise it.Any advice welcomed.Thanks.

[Kenj]

Raising the cold water tank will increase the water pressure. The bottom of the cold water tank should be a minimum of 5 feet above the top of the H/W cylinder.
The new taps that you have fitted may have a narower bore than the previous taps, especially if the tap is a monoblock type.
Also are you sure that you have not obstructed the pipes with ptfe tape of jointing compound?
Is it both the cold and hot flows that are reduced?

[bavyboy]

Thanks for the reply.Yes both hot and cold flows are reduced at the bath mixer.I think your right about the bore size.The tank is at least 5 feet above the cylinder but I need more pressure for the shower attatchment to work better.Any idea how high I should raise the tank in the loft ???.

[Kenj]

Another requirement I should have mentioned is the the bottom of the C/W tank should be 600mm above the height of the shower head. Unless you have rather low ceilings or are very tall this should not be a problem.
It is not easy to raise a water tank very far without compromising it's stability. A tank when full of water is very heavy. So the answer to your question is, raise it as far as you feel confident to do so. Personally I would not raise it more than 2 feet.
A better option is to ensure that the hot and cold feed to the bath / shower are run in 22mm pipe to as close to the bath / shower as possible.
Good luck.

[rosebery]

This always happens with the modern 1/4 turn ceramic taps and if you have fitted a bath/shower mixer then the diverter is also going to restrict flow.

Your pressure hasn't changed - it's the flow rate that has. Before embarking on raising the tank I would check with supplier on the specification of the new tap for it's flow rates at different pressures.

Your pressure is currently probably about 0.2 - 0.25bar.

What matters is the height difference between the water level in the cold water storage tank and the highest part of the tap (for the bath) and the shower head for the shower.

You'll not achieve much change by raising the tank a couple of feet.

I'd suggest pumping it.

Cheers