Water coming from water tank on city water (Solved)

Chris0152

Is this normal...I've only used city water twice...this weekend while on city water the tank seemed to fill up...I drained it an seems water still drains from there when using city water...any insight appreciated

Sharon_is_SAM

This typically points to a failed check valve in the water pump.  Are you using a pressure regulator?

Chris0152

Yes...using a pressure regulator...easy fix?

Sharon_is_SAM

Check this out.  There seems to be a potential fix besides replacing the pump.

https://tab-rv.vanillacommunity.com/discussion/6454/fresh-water-tank-mysteriously-filling-when-connected-to-city-water

Chris0152

Ran the water out of the tank to empty...did not reset pump...still leaks out tank  drain 

dsfdogs

Not sure of the year of your trailer, but if you have the Nautilus, the check valve at the fresh water inlet could be the issue. Check that the screen at the inlet is pointed/faced out. If it is, then maybe look at the white button check valve behind it, does it move? Maybe it's stuck.

Sharon_is_SAM

I thought that failure of thecheck valve for the freshwater with the Nautilus resulted in water coming out through the freshwater connection.

ScottG

Yep. Typically a failure in the city water inlet check valve will result in water leaking out the city water port when using the pump and onboard water tank.

A failure in the pump check valve will result in the onboard water tank getting filled when using city water. 

Having a Nautilus may add a few additional wrinkles depending on valve settings, but the basic concepts should be the same. 

Bill&Suze

ScottG said:

Yep. Typically a failure in the city water inlet check valve will result in water leaking out the city water port when using the pump and onboard water tank.

A failure in the pump check valve will result in the onboard water tank getting filled when using city water. 

Having a Nautilus may add a few additional wrinkles depending on valve settings, but the basic concepts should be the same. 

If the pump check valve fails it would seem that a a catastrophe will ensue once the fresh water tank totally fills and continues expanding. Are there telltale signs that the check valve has failed and that water is being diverted to the fresh water tank early on once city water is turned on? It would seem that all one could do is listen intently for the sound of water running continuously. We typically start off at a campsite with totally drained lines and drained Alde so we hear city water filling everything and then the sound stops after several minutes. I would take somewhat longer to then fill the 25 gallon water tank.

ScottG

Bill&Suze said:

...

Are there telltale signs that the check valve has failed and that water is being diverted to the fresh water tank early on once city water is turned on? It would seem that all one could do is listen intently for the sound of water running continuously. We typically start off at a campsite with totally drained lines and drained Alde so we hear city water filling everything and then the sound stops after several minutes. I would take somewhat longer to then fill the 25 gallon water tank.

Good question and point. 

Since freshwater tanks must vented in some manner (they wouldn't fill properly if they weren't) I would expect that eventually water would start emerging from the vent. (In my case the vent is located right above the FW tank fill port.) 

Even if the vent were blocked, the FW tank would only pressurize to the level of the city water source--the same thing that happens in your plumbing under normal conditions. That said, the FW tank isn't normally under any pressure, so it might well suffer a failure in these circumstances.

My suspicion (and that's all it is) is that leaks in the pump check valve are usually pretty small. As a result, water trickles into the tank rather than gushing. As such, the tank will take a long time to overflow, and you might not hear anything unusual before discovering that your once-empty tank now has water in it! 

Mickerly

What year trailer is it, or does it have a Nautilus panel. Most of the responses so far have been for trailers without Nautilus. You system is different.

Chris0152

Found out it was the water valve as you all guessed and I googled.  Replaced and good to go...by an Airstream dealer no less...fyi...better than most repair places