I've also had this problem with mine (along with many many others). The pipe connection, above the heater, on the back of the unit was lose and therefore leaking water out (all over the heater unit too, so therefore it also tripped the electric!). Put on a new pipe crimp connection and that problem seems to be solved (although it does still short the circuit breaker regulary, although to date no pools of water on the floor)
Sarah Hewitson, December 2008