Air lock in water pipe?

Aug 1, 2006
Since completely draining the water tank at the end of the summer, the tap in the kitchen area of my camper van (Globecar Trendscout) will now only work if the tap in the washroom is on, fortunately the kitchen and washroom are adjacent. Could this be an airlock? Does anyone know what I can do to cure it? Any ideas would be greatly appreciated.
Nov 19, 2010
I'm not familiar with the Trendscout, but the usual procedure for an airlock is to suck through the tap with it turned on (using a bit of flexible tube if necessary) until water flows through. Not sure why it should work when the washroom tap is on though. If it's a pressure-operated system that might have something to do with it.
Basically, there are two kinds of pump operating system. Pressure ones switch the pump on whenever the pressure drops (by a tap being open). Microswitch ones are switched on directly when the tap is turned - you can identify these by the fact that there are two wires connected to the underside of the tap - pressure ones have no wiring anywhere near the tap, it's all at the pump.
Feb 18, 2011
Hi, I had the same problem on my Hymer. It turned out to be the microswitch in the tap. How I found this was to cut the wires feeding the tap(remove fuse or turn electric off to habitation area first) & put on some connectors incase the tap was Ok. Then, not reconnecting the wires, link the 2 wires together which go off to the pump not the tap(put the fuse back/electric on). If the pump runs, then the tap microswitch is at fault.It was & so was the Thetford wc microswitch. So to save a lot of hassel,I then decided to fit the whale inline pressure switch ( this now feeds all taps, wc flush & shower, so no more pesky microswitches.You dont have to take the microswitches out, by simply disconecting the original feed to the pump & wiring in the new 12volt feed--everythings great.
This really is a simple installation.


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