The water reserve tank filled up by itself.

[Komodo]

These past two weeks I have been camping with full service. So I did not need to fill the water tank for water use. The pump is turned off.

Still, somehow, water slowly filled the water tank from somewhere. I noticed when water was spilling out of the inlet of the water tank. Yes, the cap was not screwed in properly. I emptied the tank and water started to fill from inside again????

I realy don’t know what happened.

Can anyone explain?

[Mr. Dan]

Yes… it’s a common issue reported and explained here often. For one of 2-4 reasons, pressurized city water is going past the check valve in your water pump and into your “fresh water tank”. I had it happen last week. I turned off city water and used all the water from the fresh water tank and this cleared my check valve.

[18LT]

The water pump is allowing the water to leaking back into the fresh water holding tank. The short term fix seems to be to turn off the city water supply and let the water pump cycle a few times, then turn the city water supply on again.

[Komodo]

Thank you, if it happens again, I now know what to do.

[clintbonnie73]

Originally Posted by Komodo

Thank you, if it happens again, I now know what to do.

Do you have a pressure reducer inline with your city water supply hose to your RV ? And yes, it is usually caused by the valve on your water pump..

[Komodo]

Originally Posted by clintbonnie73

Do you have a pressure reducer inline with your city water supply hose to your RV ? And yes, it is usually caused by the valve on your water pump..

Yes I do, but I was not using it this time because the campsite tap would not turn with the pressure reducer attached.

[Reverse_snowbird]

Originally Posted by Komodo

Yes I do, but I was not using it this time because the campsite tap would not turn with the pressure reducer attached.

Some campsites already have pressure reducers on their faucets and others have such low water pressure that it won't work with a pressure reducer.