Hi I have a brand new top up which has been on for about 2 weeks now and the alarm has gone of 3 times. It seems a problem with the optical sensor as sometimes it just continues on until the safety float valve kicks in but by then it has topped up about an extra 2 gallons and the optical sensor is completely under water. Is it just a coincidence that it seems to cut off on the float valve or is it syphoning out of the bucket until it levels the bucket and the sump out together?