Hot water tap washer distorts on oil system

[bosswhite]

Any solution to problem of compression/wear of hot tap washer (on kitchen mixer) ?

Water is from a Rayburn (oil) on LOW setting, but the domestic water is VERY hot.
There used to be leather washers , I'm told......

Any advice gratefully received... (sick of re-washering about 4 x per year !)

 

[Frog67]

Thermostatic mixer valve on hot water supply to tap