I had a Aqualisa Quartz power shower installed some 6 month ago which has worked very well until my daughter switched off the electricity on the hall landing. After switching back on both lights on the shower come on (i.e the on off and booster button) but no water. Occasionally it makes a few grunts like it wants to try to start. I hope there may be a simple air lock I can somehow clear as the shower is behind my newly tiled bathroom!