mira 7.5 electric shower?

shower cuts off after 1 or 2 min with the low flow light on even if i have it on hot or cold have checked water pressure ok have cleaned inlet valve little bit of limescale as on shower head tried the shower with the head off still cuts off once it goes off you have to wait about an hour for it to work again does it have a filter any where else maybe where water leaves shower for head have a feeling it could be flow valve help lol if i no what it is i could order part