Mira 8 shower

[Bigbaldgit]

I have an old surface mounted Mira 8. Since we have had a combi boiler fitted 6 months ago, the hot water pressure has increased massively compared to the old tank fed system and the shower valve clunks when turned on and off.
I am told the Mira 8 will not last long under the new pressure (although I fitted a service pack 2 yrs ago).
Can I do anything to prolong it's life, or is there anything I can directly replace it with without disturbing the tiling?

[doitall]

Pressure reducing valve.

No forget that its toooooo obvious.

For what its worth if you read the manufacturers instructions it says.

Hot and Cold supplies must originate from a cold water cistern and NOT directly from the cold water mains.

But they was written 25 years ago.