Upstairs hot sink tap does not work properly anymore. Why?

thor

My upstairs sink hot tap randomly does not work. Usually now when I turn it on, nothing comes out. Not always but most of the time. When it does work the water is hot as it should be but I am puzzled why this is happening. The bath hot tap runs without problems at all times.We have a 2 year old vaillant central heating boiler. Could this be the cause of the problem? If not then what else could be at fault?

Browntoa

Tap valve probably sticking , simple replacement job

mrprosser

Is it a mixer tap?


A plumber showed me a trick when our mixer tap wasn't delivering hot water.


Turn on the hot tap, cover the hole for the water with your thumb


Gently turn on the cold water.


As the cold water cant get out of the tap it is forced down the hot pipe. That purges the airlock stopping the water getting through.


See what happens

thor

It's not a mixer. It's just a standard turning tap. I'll open it up and have a look to see if there is nothing obvious causing the problem(maybe there is something causing a blockage).