Please diagnose my sodding (not so) hot tap

[bigandclever]

Seeing as all the experts are on ...

The (thermostatic) bath shower mixer tap in my bathroom doesn't produce hot water. The boiler fires when hot water is requested but no hot water comes out of the tap - only cold.

In the same bathroom, and presumably on the same system, there is a basin. The hot water comes out fine from that (monoblock) tap. The shower and basins downstairs, that are also presumably on the same boiler/water system, also work fine.

The previous owner said that this had happened before and it was a build up of limescale in the tap that was cleaned out and the problem stopped. We are in a hard-water area, so I can sort of believe it.

Does this diagnosis sound reasonable, and if so, what can I do to resolve it short of smacking it with a hammer and throwing it out of the window?


[not a real man]
I have no tools. Apart from a hammer.
[/not a real man]

[Ferg]

I'd say scale.

[bigandclever]

Ta. With the tap in situ is there anything I can do to encourage unblocking?

[kinabalu]

Doesn't this indicate more that the thermostat in that particular mixer has gone? Had this with a shower once, some stats are small cartridges in the tap which are replaceable.

[bigandclever]

What's the punishment these days for punching 'tradesmen' in the face? Not content with not fixing the tap (although a new heat exchanger, bigger bore pipes, new isolator valves, new pump, and all manner of other bks was "definitely needed", before they'd even opened the front door of the boiler) when the 'professionals' the missus called to sort it out actually deigned to look at the tap, they smashed the side of the bathtub. "Innit bruv" in-fking-deed. aholes.

I know no-one on here cares, and of course I didn't lose my rag that much to actually slap someone. But let's see what 'the boss' has to say about how what he's going to do to rectify the situation tomorrow