Bath Mixer Tap Problem - no hot water flow!

I hope someone can help me!

I have a mixer tap with a shower attached on the bath. Last week I noticed that the hot tap flow had started to reduce and it is now at a complete trickle only! The other hot taps in the house remain fine - all served from the same supply.

The cold tap runs fine from mains pressure.

Does anyone have any idea what it may be. I have had not work done on the hot plumbing but did have an internal water meter fitted just before this started to happen (probably just a co-incidence)!.

Any suggestions would be great. I do live in a very hard water area so am wondering if it is limed up in the pipe - if so what can I do about that?

Thanks

Kate

First action is to turn off the hot water and remove the bath tap hw valve. Briefly let the hw run and see what comes out, then inspect and clean the valve as it's probably blocked with scale.
As your other hw taps flow normally it is unlikely the DHW cylinder outlet is scaled-up, nor the secondary HE if you have a combi.