Power Shower Problem

The last few days the water coming from our power shower isn't very hot, just lukewarm. The water coming from our taps is very hot so I know there is definitely hot water available. We had the local plumber look at it a while back and he cleaned some dirt from the filters(?) and that definitely seemed to help but the problem is back again now. Firstly I'm wondering can I clean the filters myself but I'm unsure how to go about this...

Secondly I'm wondering if the thermostat could also be part of the problem? The shower is about 4 years old.

Any help/advice appreciated.

Where is the power shower water fed from? From hot water cylinder or from tank in attic? If from attic the supply may be off bottom of the tank and dirt is getting into the line and hence into shower

Limescale. Open up the head and clean it out. Sounds mad, but it actually works

Thanks for the replies!

Chlipps: I assume that it's fed from both. Hot water from the hot water cylinder and cold from the tank in the attic?

Packard: I've cleaned the limescale from the shower head before but it was a good while back. Will give it a try anyway. Don't see how that would just affect the hot water though ?

agree with packard, we had a guy from Triton out some time back and he recommended running your shower for 10 secs using cold water when finished to prevent limescale build-up. Get a spare shower head & leave the original shower head overnight in some common cleaning agent and yes it works...

My electric shower is not very hot at the moment, I put it down to the fact that the water temperature coming in to the house is so low the shower cannot cope.