Low cold water pressure

[Davy Monroe]

Hi,

I frequently experience low cold water pressure in my bathroom to all appliances (bath, sink, toilet, shower), whereas the hot water pressure remains fine. This is intermittent - it used to be that after running cold water for a long time (eg filling a bath) the pressure would sometimes drop, but its now often like that when nothing has been run for ages.

The cold water is coming from the tank in the loft and I checked this and it was full.

Any one got any ideas what could be causing this?

 

[gas4you]

Check that there is not a blockage in the pipe work from the cold loft tank. Try back filling on an upstairs cold tap with a hose connected to mains cold pressure

 

[Davy Monroe]

Thanks for that. The back filling worked a treat.

 

[prestonbloke]

My cold water taps upstairs developed exactly the same problem. I went into the loft and the tank was filling fine. It became clear that the problem was an air lock.

So rather than pay a plumber to do something straight forward I borrowed a garden hose from a relative and tried back filling, but my crappy 'designer' taps couldn't provide a secure and water-tight seal for the hose and therefore could not clear the air lock.

Then I decided that if I empty the tank this in itself may clear the lock - so after turning off the mains supply, in the bathroom I turned on the basin cold water tap, then the bath cold water tap and both just trickled - then I flushed the loo.

After about 5 seconds of gurgling the loo suddenly emptied and both cold water taps sprung into life and were flowing better than ever. Now everything is tickety boo! So trying everything at once must have forced the air lock out of the system - Result!

 

[harryhoc]

Check that there is not a blockage in the pipe work from the cold loft tank. Try back filling on an upstairs cold tap with a hose connected to mains cold pressure

Thanks and dumb question but can you describe how to do the "back fill" action. Cheers

 

[bolshy]

Get a hose connected to mains cold water - kitchen tap will be mains. Connect the other end to a bathroom tap fed from the cold water storage tank. Turn on both taps, the mains water will flush through into the storage tank, be careful not to overflow it, a minute or so should be plenty to flush through any blockage. This should clear airlocks too. Your stored water may be cloudy for a while after doing this