stoptaps and air in pipes???

[Jennie]

Hi all,
Just wondering if I missed something on a job today?
A simple job - to rewasher a basin tap.
The house was on a combi boiler (which I switched off) and then turned off the internal stopcock under the kitchen sink. Water still trickled through the cold taps even after a couple of minutes, despite my opening the upstairs taps (to let any extra water out of the pipes).
So I turned off the stopcock in the street, which helped - but still water came through the cold taps. Nothing much out of the hot taps though (I was changing a hot tap washer, which was fortunate).
When I turned the two stopcocks back on, a lot of air came through the taps. It was only a small house, but I've never seen so much air come through after turning the water off. It took a few minutes of running the taps to clear it all.
Any tips/insights would be much appreciated.
Thanks,
Jennie

 

[lame plumber]

opening the upstairs taps will cause additional water to drain out, best to leave shut and just drain the tap you work on, less hassle that way. if you isolate the boiler cold water in there is no need to touch any other valves, less chance of breaking something as well.

 

[JCplumb]

If you were working on an upstairs basin then opening the kitchen taps will prevent any water from reaching the upstairs while you work if the stopcock is passing.

 

[willing2learn]

opening the upstairs taps will cause additional water to drain out, best to leave shut and just drain the tap you work on, less hassle that way. if you isolate the boiler cold water in there is no need to touch any other valves, less chance of breaking something as well.

Just be careful, as quite a lot of isolation valves on older boilers tend to weep once turned!