Water Pressure Help

[WillWriter]

Hi all,
I am new here but have used this site for a lot of reference over the past few months and have found it to be a great site.

I have recently moved into a house (approx 11yrs old) which has a turbine pressurised water heating system controlled by "Heatwise". I am not sure why I mention this but it might be relevant to my question.

My problem is that I have very low hot water pressure upstairs in all of the bathrooms (the bath takes ages to run) and if I run 2 taps at once it falls to a trickle. I am a novice at plumbing but I have made sure the stopcock is open.

Can anyone offer any advice or help?
Cheers
steve

 

[MANDATE]

The flow of water from a tap is caused by the 'pressure' overcoming any 'resistance'
Increased flow is achieved by increasing pressure or reducing resistance.
Sometimes replacing taps affects the flow when the bore of the tap is smaller than the tap replaced.
Hot water pressure is low compared with cold water pressure from mains supply. (except for a combi where they are both the same)

The pressure is determined by the vertical position of the Cold Water Cistern/tank usually housed in the attic space.
My CW Cistern is housed in the bathroom about 18ins above the hot water cylinder and there is insufficient pressure to operate shower in the bath room.
We tried a shower handset on the bath taps. not too bad for rinsing hair at low level but flow went to nothing when lifted up to head height.
Of course if two taps are open then the flow will be divided
I can only think that there is a partial blockage somewhere before the pipes divide to the taps.
Obviously you cant compare upstairs with downstairs, as downstairs vertical distance to cistern is greater there will be greater pressure.
A blockage would still have an effect downstairs, but perhaps not so noticeable

 

[WillWriter]

Thanks for taking the time to reply, how can I check if there is a blockage ?

 

[kirkgas]

Thanks for taking the time to reply, how can I check if there is a blockage ?

once you have checked the valves are ok and fully open, you could (if you have the bits and bobs and the right washing machine) disconnect the hot and cold wash machine hoses (some machines are cold fill only) and join them together, then turn them back on and back fill the hot from the cold, you will then need to check how quickly the water gets back up into the loft tank and see if you can see how quickly it fills into the tank, this should/could dislodge a blockage and refilll the tank quite quickly from the bottom, you will need a hand to check between the loft and kitchen to shut off the valves etc before the tank refills too quickly,

 

[WillWriter]

Damm, only have a cold feed machine

 

[Axel]

Can do that with a kitchen mixer tap if there are no check valves on it - hold your hand on the spout with cold and hot taps open. You will get wet.

 

[WillWriter]

So run the mixer tap in the kitchen (both hot and cold) and put my hand over it to try and stop it and this should unblock any blockage?
Cheers

edit to add - could i do this on the bath mixer tap?

 

[Axel]

Maybe, if no check valves are fitted and bath cold is on mains, but it's probably on the tank. If the bath tap is on mains cold and gravity hot and has a shower divertor beware that hose or head blockage could backfill the tank.....