how can i get my mira advance thermostatic to work?

i had my new shower installed a few months a go and several times the start stop button started flashing rapidly and the shower turned itself off but after approx 20mins it sorted itself.now this morning when i pulled the power cord it was flashing straight away and its been hours and its still not working.i always use following user guide and neither the reset or water supply lights are flashing.can someone please help? Its a mira advance atl thermostatic