Why are my faucets farting?

[keeena]

I'm already going to dig into this, but figured I'd try to get some opinions.

My water system is dispensing aerated water (air in the water; spits and farts) when on the water pump. The water pump also will not shut off when faucets are closed. I assume its because it can't reach pressure due to the air in the lines on the pressure side of the pump. This will not happen when hooked up to city water. I've read that this is due to the input line from the fresh water tank being loose. I've checked this and the pump's filter canister prior to the pump and they seem snug, no leaks.

The system was fine until I had to remove my freshwater tank when doing my axles. When re-connecting it: I took some care to tidy up all the lines (fill, vent, supply) because they were wrapped around each other. Mentioning in case a dip or "trap" is necessary in the supply line? The system isn't leaking anywhere.

During our first trip on city water: I noticed that the city water was filling the fresh water tank. Obviously a check-valve issue. I turned the pump on and gave it some percussive maintenance and it seemed to fix itself. Mentioning in case a bad check valve could cause this air problem (I doubt it) as well as potentially damaging the pressure switch with said maintenance...

Seeing as there's no water leaking: I don't see how air can get INTO the system. My only thoughts are to run a temp line directly to the pump to test and also just pull the pump apart to see if I can find anything suspect. Any other thoughts?

[keeena]

Found the problem; tank R/R and check-valve quirks sent me on a wild goose chase.

When I winterize the camper one of the things I do is remove the pump screen filter. Apparently the o-ring in the filter canister fell out while it was removed. The pump was pulling air in past the threads since they are not sealing by themselves. Luckily I had an o-ring which was close enough and that fixed the problem.

[Merlin]

Yay!  Glad you found the problem.

[keeena]

In case its useful: the exact o-ring for the strainer cup may be hard to source (its a rectangular profile), but a very very close standard part would be a fractional 1/16 inch thick o-ring, size "-027" (that reads as "dash 027).

You would have to buy packs of 100 if going to a supplier (i.e. McMaster-Carr link), averages about 0.12c each. A good hardware store may carry them individually, but expect to pay a few bucks. HTH!