Hi Vlad
Now I havent tried this yet but Mira say that it is air in the flow valve.
The solution is to run the shower with the head off for 3-4 mins and the pipe hanging down to the floor. Start with the temp at full cold and slowly move it through to full hot.
This they reckon will clear it. As I say I'm yet to try.
Good luck
Mira Showers 0870 241 0888
Tim
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