And I'm not being taken in by anything, I am being a user of a Selectronic who not once in over 7 years has suffered the "Ouch &*^%£$"@#!" when someone flushes the loo or turns on a cold tap, unlike I did many times when I had a boggo standard Triton with nothing but a crude thermal cutout.
That's only cause the redring works on a min pressure of 0.7 bar and triton work on 1.0 bar.
That just indicates you have lousey mains pressure.