Community Forums

JohnnyJohnso · 03-06-2014, 10:35 PM

Under my bathroom sink, I have 4 Poly tubes coming up to sink. Two are the hot and cold water supply. The other two go up as high as the sink and there is some sort of a valve with a flow direction arrow on it. Straight up and right back down, From the appearance of the tubing there has not been any water in these tubes. lately a few water drops come out of this valve and will run down the tubing into the storage area under the camper. I though all air admittance valves were on the large drain pipes and not the Poly tubing. I have no drain problems and all sinks work fine. Anyone know what this component is and why water drips out of the cap area?

Thanks
Johnny

JohnnyJohnso · 03-06-2014, 10:48 PM

I have flush nozzles on my black water tank. Could this problem be connected to when I flush the tank. Since I have a potable water faucet and a extra faucet at my campsite I leave two hoses hooked up all the time. One for supply and one for flush. Makes flushing simple and don't have to move hoses and get air in the system.
Thanks
Johnny

Walt Bennett · 03-07-2014, 02:26 AM

That's the back-flow preventer for your flush system. Lucky you that it's right there under the sink and you can replace it easily. Some Monty's have them in a wall or some other really hard place to find. Makes it seriously bad if the valve fails and leaks. I've seen a few posts on MOC where people have just eliminated the valve, leaving the loop of plastic pipe serving as an air gap.

JohnnyJohnso · 03-07-2014, 05:50 AM

OK..For some reason, I though that the tubing for the flush nozzles just went from the garden hose connection straight to the nozzles and were open ended at the nozzles. Next time I empty the black tank, I'll check to see if that's when it leaks. Does the check valve have to be in the upright position to work? If not, I could take it out from under the sink and install the new one at the poly connections in the storage basement. There are two connections there that go straight up to the sink/check valve.

Thanks
Johnny

Walt Bennett · 03-07-2014, 06:30 AM

I don't think it matters. The 'manual' we got with our new/used one just shows how there's an inverted U with the check valve at the top. I'd imagine that's so there wouldn't be any trapped water that'd freeze in the winter. The main thing is to not have any water flow backwards from the tank side.