thermostatic shower may need a service?

[6sunrise]

Hi - I have inherited with my 'new' house, an aqualisa thermostatic shower, model 609, probably about 5 years old; having been at my new home for 2 years, the unit is getting more difficult to temperature set, control needs to be moved further towards hot setting to get same as before when set more towards central), also controls are stiffer to move; can the unit be dismantled and decscaled using a kettle descaler, and then refitted (with new seals and silicon grease of course), or do i need to buy a new cartridge (£90 plus) for it?

[stoneyboy]

6sunrise,
Better to buy a new cartridge which comes with new seala and screws.
end

[6sunrise]

hi - thanks for advice!!