Wickes Alure mixer shower temperature issue

[Wezza911]

Had a new shower installed.
Wickes Alure Round Thermostatic Mixer Shower - item no. 299680.
There is no mixing: it's either cold or scolding hot!

When the shower is turned on in the neutral position, the water is cold.
Turning it away - it gets hot & stays hot even when turned towards as well!

Any ideas what the issue is?
Thanks,
Wezza

 

[CountryFan]

Thermostatic cartridge could have failed, debris in supply, unbalanced supplies to name some instances. Who fitted the shower? Maybe if not yourself, get them back to fix it or replace.

 

[Wezza911]

Thanks for the reply.
It was installed as part of a bathroom refit.
Typically, the guy's scarpered now.
Will investigate what you suggested.

 

[danfre]

Hot and cold supplies wrong way?