shower pump pressure problems

[beany73]

I need some help; I am not very knowledgeable in the details of plumbing. I have recently had a new en-suite shower fitted and I’m disappointed with the pressure. My system is gravity fed, the cold water tank in located in the loft above the new shower and the hot water tank is on the same level as the shower in another room.
The plumber used a 1.5 bar pressure pump and said that he cannot use a stronger pump because my water cylinder is too small and will be drained of hot water too quickly. The cylinder is 1050x400 with a capacity of 114 litres (that what it says on the front?!). Is it true that my cylinder is too small? If it isn’t - what pressure pump would you recommend? If it is – is there anything I can do to increase the pressure?

 

[ChrisR]

Pressure and flow are very different. Water speed is relevant too!. First measure the flow, time to fill a 9l bucket say at showering temp.

If you use a shower head with small holes you get faster water, but less of it.
It depends which you prefer - bucket of water over your head is high flow low pressure, fine needle jets which hurt are high pressure, low flow.

You do have a fairly small tank - reasonable flows are usually 10 - 20 litres/minute.

 

[beany73]

Thanks for that.
I did the water test and it took 40 secs for 9L - which works out to be in the reasonable flow rate. I guess what i wanted was water that hurt - so maybe what I need is a shower head with smaller holes - ie more pressure.

When the plumber says a higher bar pump would drain the tank - does he mean I would have to have the hot water on for longer before I take a shower in order to have a hot shower - or does it mean I will run out of hot water regardless of how long the hot water has been on for?
Thanks

 

[Direct plumbing]

Hi,
I gather that your ensuite is situated on the upper floor of a two storey property. If so, the reason your pressure is low, is due to your cold water storage cistern being situated approx 1 metre above your shower head. This would give you a very low (what is called) head of pressure.
The way it works is, the higher the c.w.s.c (cold water storage cistern) is located above your shower head, the greater the (head of) water pressure. Unless the shower is fed via a direct cold water system; in which case you would be laughing.
You could have a pump fitted; but the time you spend in the shower would have to be reduced, because as stated before, your cistern would empty faster than it would fill. Sorry mate.

 

[ChrisR]

Beany
you'll be using about 2:1 hot to cold, so you HW will last approx 114/9= 11 minutes