I've had a lot of problems with hot water running cold, from ferroli optima 901, it wasnt the thermos on the pipe, or the flow sensor, I now think I've sort of solved it, the air pressure switch seems to be cutting out the boiler ( not the flame, just the on/off, is there some sort of switch which means this needs to be level, when I move the air pressure switch the system cuts off, it might be a faulty wire, however when I lay the air pressure switch flat it works, Is there some sort "switch" in there that means it needs to be on the level, if not then I will get a new switch and wire. Thanks