No hot water from sink in bathroom, but everywhere else is fine in house

[adamtheplumber]

Hi, first post here on the forum.

Been having a look through and a search of the site for help, but couldn't find the answer I wanted, so thought I would have an ask here.

I have been asked to have a look at a friends bathroom, which has no water from the hot tap in the bathroom, but the hot works fine on the bath.
If i open the hot tap right up, and turn the cold on full blast, as small amount of water ( read dribble ) starts to come from the hot tap.
Have had a look under the sink to double check the service valve isnt turned down/off, but alas as its an old house, there is no service valve, just a hot water stop valve elsewhere in the house.
Would you think this sounds like an airlock, or do you think the tap needs pulling apart and checking for debris?
Any help would be much appreciated,
Many thanks
Adam

 

[Dotty]

Strip the tap down.

 

[adamtheplumber]

Cheers mate, would the best bet be...
Turn the fuse off for boiler and remove,
Turn the cold feed off to boiler ( or alternatively turn off the hot feed at the stop valve )
Drain sytem through the bath tap
Then take tap apart the tap, turn cold/hot feed back on, re-fit boiler fuse, and then turn hot tap on and wait for it to start letting water out?
Thanks very much, I appreciate this may be a simple thing to do, but i just wanted to make sure i get it right.
I've nearly finished my plumbing course at college so I have a fair idea what I'm doing, but as I have started to discover, it aint as easy outside of the college workshop!
Cheers bud

 

[Drew Greenfield]

If it's a system with a DHW cylinder there should be a gate valve near the cylinder on the pipe that feeds into the bottom of it that should be turned off, then you could strip the tap, clean it and put back together with a smear of WRAS approved grease/paste, new washer and a re-cut seat.

 

[johnmcginty]

Swap the tap gland over, mind you though if it is an old gate valve they can easily break in off position.

 

[adamtheplumber]

All sorted in the end, tap turned out to be over 15 years old, and unsurprisingly didnt want to come apart no matter what i tried.
Still, they now have a nice set of new taps which look much better, thanks for all the advice, really is appreciated.