Restricted hot water flow

[pmx_super]

I have a gravity fed system with a Salamander RHP50 only feeding the bath mixer tap with shower attachment. The pump is 18 months old and the installation is all in order with 22mm feeds in, a dedicated cold and Surrey flange on the hot.

The mixer tap is rather old. It was in place when I bought the house and I'd guess 15+ years. Intermittantly I find that the hot water flow is worse than normal, but the cold is always ok. It fixed itself a few months ago, and again 2 days ago, but it's happened again this morning so it appears to be becoming more frequent.

I'm guessing that it must be a fault in the ageing mixer tap, but I wanted to see if any of the experts on here would do any tests on other components in the system before forking out the money for a new tap?

 

[pmx_super]

The taps are the old washer type. I've only just realised that the hot water tap now only spins half a turn. It definitely used to turn more that that - the cold one does 1.5 turns. Is that something obvious that can be fixed?

 

[Whitespirit66]

Have you checked the pump's filters?

 

[TicklyT]

If the tap headgear's movement is restricted it may be on it's way out, or bunged up with limescale.

Stripping down, cleaning and re-greasing it may do the job.

Or replace the headgear with a tap reviver kit.