Coming out of the webasto/aquahot are 2 copper pipes that protrude under the bottom of the bus. They appear to be have small popoff solenoid valves like you have on your hot water heater at home but much smaller. They are in fact SMC solenoid Valves part number VXD 2130. One of the valves is letting water drip thru. Called SMC distributor and they went to SMC and nobody can find that Part Number. Any suggestions are maybe another source. What is really intriging is that it is clean water and I thought webasto/aquahot had all water with antifreze. By the way webast o works like a charm!! HELP DAN (Pic attached)