Although ALL of the alarms in 13 years have been because of flow alarms to the generator. Whe we suck-up a nettle, eel grasss, etc., or the impeller has a problem, we've gotten alarms on the generator. Because the sensor on flow is based on the hose size (which is oversized for the actual flow), the flow sensors are very sensitive. In any event, if the alarm goes off -- we're going to be checking it out below first.