Grey water tank filling from city water

[bearded19711]

I’ve got a 2016 22 Sport that I’ve had for a couple of years, but still consider myself a newbie because I haven’t had any problems until now.
We’re on our first trip of the year, just starting a 6 week trip out west but did not de-winterize until we got here in the FL panhandle. Within a half day after hooking up to city water here at a state park, the grey water tank filled up, and not by us using water in sinks or shower, we had used very little at that point. The digital level readout (always unreliable) read zero but the shower drain started gurgling when we used a sink, and the sink water didn’t drain. I went out and drained the black tank first and got what seemed like the right amount out of it. Then I drained the grey tank and it flowed forever. Sinks started draining immediately. This whole scenario happened again within a day.
Since then I filled my water tank and disconnected from city water. No problem with this scenario.
Question: How is my grey tank filling from city water without using sinks or shower?
How can I fix it?
Sorry for the long post. I tried searching the forum but am limited to my cell phone here at the park.
Thanks for any help!!

[daleyocum]

Quite the mystery! Are you absolutely sure the grey tank was empty when you hooked up to city water and wasn’t overlooked in the winterization process?

[OTRA15]

Originally Posted by daleyocum

Quite the mystery! Are you absolutely sure the grey tank was empty when you hooked up to city water and wasn’t overlooked in the winterization process?

The OP said it happened again, after draining the grey water tank.

Originally Posted by bearded19711

. . .
. . . This whole scenario happened again within a day.
. . .

bearded -- when you are hooked up to city water, have you looked carefully for leaky faucets, especially during the night? Try turning off city water at the hose bib, except when you need it. Use the water tank for flushing during the night, etc.. In other words, try to adjust some of the variables. Chances are good you will get a handle on this IMO.

Good luck,

Peter

[bearded19711]

Thanks for the responses! Still puzzled. Got a call in to Colonial Airstream where I bought it. The first guy I talked to was puzzled too! A more experienced person is supposed to call back. Keep your thoughts and guesses coming! I’ll let you know what the solution was when we solve it!

[OTRA15]

Originally Posted by bearded19711

Thanks for the responses! Still puzzled. Got a call in to Colonial Airstream where I bought it. The first guy I talked to was puzzled too! A more experienced person is supposed to call back. Keep your thoughts and guesses coming! I’ll let you know what the solution was when we solve it!

Are you sleeping in the trailer tonight? Try the suggestions in Post #3 . . . no need to wait for an "expert" to comment. You can become the expert for your Airstream!

Peter

[AlinCal]

The only connection between city water and the grey tank is thru the faucet, if its not running/dripping it cant happen.
This would be a serious health risk "if" someone did some creative plumbing to make it happen, not from what ends up in the grey tank but what could end up in the city supply from a cross connection.
As Peter is saying you need to verify with a few tests.

[daleyocum]

Just had a thought. Since the trailer just came out of winterization could there be a bypass valve still open now that wasn’t open before? Maybe even a valve that wasn’t plumbed correctly but didn’t show up previously because it was shut.

[jimfa440]

Check your city water pressure regulator. If it is set high or not functioning, you could have way too much water pressure, not available from your fresh water tank pump.
An easy way would be to install a water pressure regulator at the spigot.

[WhereStream]

There's another person on Airforums seeking a explanation to this same problem.

[smithcreek]

This is a drawing of typical AS plumbing. Two pipes go into the gray tank from the various drains and there is one vent pipe. All these pipes are large diameter pvc.


I don't see any possible way to accidentally tie in the 1/2" fresh water pex piping to a drain pipes. The only reasonable way for water to enter the gray tank is through one of the drains. I'm going with leaking faucet.

[Lucy Goosy]

I had the same problem last year. I accidentally used a different, smaller white hose to connect my fresh water. When i saw the dripping and filling of the gray water tank I added a water pressure valve at the source and that ended the over flow. Weird but true...
Good luck

[AlinCal]

Originally Posted by Lucy Goosy

I had the same problem last year. I accidentally used a different, smaller white hose to connect my fresh water. When i saw the dripping and filling of the gray water tank I added a water pressure valve at the source and that ended the over flow. Weird but true...
Good luck

When you "saw the dripping and filling the grey water tank" are you saying the faucet was dripping into the drain?

Personaly I would never leave my trailer hooked up to city water 24 x 7, especially with no regulator and no sewer connection.

[Lucy Goosy]

Originally Posted by AlinCal

When you "saw the dripping and filling the grey water tank" are you saying the faucet was dripping into the drain?

Personaly I would never leave my trailer hooked up to city water 24 x 7, especially with no regulator and no sewer connection.

No there was no water dripping from faucet. I think the smaller hose created more pressure. I went back to the hose that came with the AS and put a regulator on it.

[Al and Missy]

A hose cannot create more pressure. In fact, a smaller hose will induce a pressure drop with flow. When there is no flow, the pressure will be the same regardless of the hose diameter. It's physics.

If it is fixed, it is fixed because you added a regulator.

Al

[GCinSC2]

This reads like a Click and Clack Cartalk puzzler.

And the answer can only be 2!

Ok nuff of that.

Here’s my dumb Friday question idea.

During this tank filling gremlin, was it raining profusely ?

[AlinCal]

Originally Posted by GCinSC2

This reads like a Click and Clack Cartalk puzzler.

And the answer can only be 2!

Ok nuff of that.

Here’s my dumb Friday question idea.

During this tank filling gremlin, was it raining profusely ?

I miss CarTalk! Those guys were the best.

I think its the white hose that does it.

[OTRA15]

Originally Posted by bearded19711

. . .
. . . I’ll let you know what the solution was when we solve it!

Did you hear from Colonial or try any of the earlier suggestions?

Thanks,

Peter

[GCinSC2]

And the answer is?

[majorairhead]

Originally Posted by GCinSC2

And the answer is?

Weird.

[GCinSC2]

Originally Posted by majorairhead

Weird.

Not real weird. The problem from the OP has folks scratching their heads saying that’s weird.

Hoping we get an answer from OP to close the circle.