Top-load washer - unexplained discharge Solved

The note below recounts laundry flooding that caused extensive mould growth and building damage.  The water flow apparently came via the hot tap to the washer, but it is not apparent how or why the leakage occurred.  Any suggestions would be welcomed.

Upon return from a five-week holiday we found the floors of the laundry, adjoining passage, storeroom and garage awash with water.  The ceilings of these rooms had extensive mould growth, and the undersides of shelves were covered with drips, indicating that hot water had caused air saturation and subsequent condensation.

Power to the ten-year-old Kleenmaid model KAW651 WG3050 clothes washer had been turned off during our absence, but the taps left on.  There was no evidence of continuing water flow upon our return except for some dripping noise which we were unable to trace.  However, there was evidence of recent flow in that the hot tap was hot.  Both washer hoses were intact, with no evidence of leakage.

All doors in the vicinity (hinged and sliding) had more or less jammed due to timber swelling.  Damage to contents was extensive including direct water contact (particularly of items on the floor) and extensive mould growth..

The washer bowl contained around 50mm of water, suggesting that it had not filled to overflowing unless it had inexplicably drained.  Metered electricity usage during our absence had, ten days after departure, jumped from around 8 KwHr per day to around 15KwHr per day.  This suggested that heating to maintain a hot water flow had continued through the remaining time of our absence.

Upon restoring power, the washer ran for a few seconds before tripping the earth leakage relay.  Each attempt to restore power yielded the same result until the entire area including the washer had been thoroughly dried out.  Thereafter the washer performed normally, running through its full cycles with no leakage. This behavior confirmed that the power to the washer had been switched off during our absence.  It had remained isolated until some twelve hours after returning home when we switched it on again, yet there was no evidence of significant flow during this time apart from the small dripping noise.

The cause of the flooding remains a mystery.  Did a valve in the washer open, allowing water to escape?  If so, how did it escape without leaving the bowl full of water?  How did this happen given that there was no power to the machine?

After restoration works we will be in a position to reinstate the machine and return to normal operations, though we will clearly have to turn off the taps to the washer whenever it is not in use to prevent the possibility of a recurrence.