Diagnosing an Electric Shower fault

[BigBL]

Model: Mira Advance ATL Flex 9.0kW Electric Shower

I'm no longer able to use 'High Flow' mode as the shower cuts off. The shower also now cuts off when the toilet is flushed.

There doesn't seem to be anything wrong with the water pressure so it would seem something inside the shower has failed.

 

[terryplumb]

The flow through the shower may be restricted ,kinked hose ,blocked filter, shower head partially blocked with limescale.
If you turn fully anti clockwise the water flow control knob and put the heating elements on the high setting ,what's the result ?

 

[BigBL]

https://streamable.com/tyl4i

It doesn't seem to be the hose or showerhead.

 

[terryplumb]

The flow doesn't look very strong to me.
Your shower has an inlet filter ,that should be replaced annually ,has this been done ? Its about the only thing the householder can do on the model you have. The fact that the showers flow cuts off when the toilet flushes ,even on the low setting ,is indicative that the shower water supply isn't good.
How old is the shower ,and have you noticed any drop in its performance ,prior to the current issue ?

 

[BigBL]

I replaced the filter today, as far as I know it's the first time it has been done. It does not seem to have made a difference.

I'm wondering whether to call United Utilities. They have recently been working on a house opposite but I do not think that that was the cause of the issue.

Also, recently, the combi boiler has repaired. A part - something to do with pressure as the old one broke was fitted.

 

[terryplumb]

And the result was........?