Low water pressure from gravity fed tank

[goldridgeg]

Hello,


We moved into a new build 2 story townhouse 6 months ago. Recently we had a faulty ball valve in our cold water gravity fed water tank in the loft – causing an overflow of water out the building.

The building plumbers came by to repair the fault but since then the water pressure has dropped to about 10% what it was in the cold taps on the basin and bath – to a slow trickle. Hot water is okay, and the power showers are okay. I have been in to the loft to see if all the valves were reopened fully, and they were okay.

What could possibly have caused the drop in water pressure, any ideas or suggestions please?

 

[Agile]

Dirt obscuring the tank outlet?

Tony

 

[goldridgeg]

Thought about that. What do you reckon I do to check and clear it

Oh and thanks for the prompt reply

 

[holty]

are you sure its cold water storage fed supplys. as it being a new build all cold outlets should be mains these days .have you tried seeing if the mains stop tap is fully open. as a very closed one will give symptoms of low pressure when actually its low flow.

 

[goldridgeg]

Definitely cold water tank fed. When it was leaking, I checked the valves and stopped the tank filling as I went along in the loft. Will check the main tap, but the down stairs pressure is perfect, in the toilet and sink etc.

 

[xr4x4]

If he drained down the tank to change the ball cock (if so I'm not sure why) some scale might have got stuck in the tap.

Does the tap have a strainer in the spout, if so, try poking a small screwdriver up it.

 

[holty]

turn a main tap on downstairs. whilst the problem tap is running. if you see a difference in flow from the problem tap. then your suggested taps are on mains. if not the cws outlet, regardless of the ball valve. should be investigated.

 

[ChrisR]

Arrange , probably by combination of hoses, a mains supply which you can use to connect to the bathroom taps and push backwards.
If you're unlucky you might have non-return valves, but probably not.

 

[bernardgreen]

Arrange , probably by combination of hoses, a mains supply which you can use to connect to the bathroom taps and push backwards.

Also works ( most times ) to remove air locks in the pipes.