One half of a mixer tap stopped working.

[un1corn]

I have a mixer tap on the bath, and an immersion style system. It's gravity fed so the hot water flow has always been weak.

Today the hot bath water was a trickle. I turned it off and back on again, it spluttered and then nothing. Now no hot water at all comes from the tap. Hot water comes out of the sink taps at the usual rate.

The tap head just lifts straight off (unlike the cold which is odd) and I can turn the mechanism by hand, but still now flow, so I know the problem isnt with the lever. The 'turn' of the tap feels more loose than usual. The tap is the same as this;



I found this diagram online, and the setup seems to be the same. I can turn number 2 by hand freely. My best guess is that number 3 has somehow broken. If that is the case, are these easy to replace with basic DIY tools, is it expensive, and do I need a plumber? I assume I would isolate the water and then drain the tank before working on it.



Thanks

[sherman]

Part 3 of your diagram is abiut £15 for a set of 2cfrom b&q etc probably cheaper online. You just need to make sure you have the right size for your tap

[ThunderSpook]

If you’re lucky you will have an isolator for each supply underneath the bath. You can just isolate it here if you can.

[Dr Mike Oxgreen]

ThunderSpook said:

If you’re lucky you will have an isolator for each supply underneath the bath. You can just isolate it here if you can.

And if not, then fit isolator valves while you’ve got the water switched off.