Electric shower noise

[lsw235]

I turned off the Stop tap so that I could repair
kitchen single-hole mixer tap(cold).
Then opened the tap to allow the water to
come through again.
Now when we run the shower in upstairs bathroom
and turn the (thermostat?) to hot the shower makes
a whining noise, turn it to cold and the whine goes away.
Any ideas. tks Bill

[justyboy]

HI there, i am assuming you have an electric shower. if so it sounds as though you have an air lock and the pump is running partly dry.certain shower units, redring and mira. for example have an internal bleed valve/button. this is normally next to the water/ heat exchanger. this valve is mechanical not electrical. most showers though, will eventually bleed themselves,