over filling

Do you have a separate outside manual water fill?

If not, for RVs without the outside manual water fill they use a manual valve inside the RV to fill the water tank. That valve may be open slightly allowing water to slowly fill the tank.

If you do have outside manual water fill, the only way water can get into the fresh water tank is if the 12V water pump check valve fails..

In this case you need to check the hose on the input side of the pump (which goes to the freshwater tank) and see if there is water coming out of the input side of the pump with the city water pressurized.

If water pump check valve has failed, you might be able to get a rebuild kit or if you can't find parts you will need to buy a new water pump..

If you don't use freshwater tank at all and have no intentions to ever use it, you could add a manual shutoff valve on the output side of pump and simply turn off the valve.

Doesn't matter what type of fresh water tank fill system that you have for your trailer, water can still leak past the pump internal check valve, filling the tank.

mobeewan wrote:
Doesn't matter what type of fresh water tank fill system that you have for your trailer, water can still leak past the pump internal check valve, filling the tank.

Not quite true. With our system, when all the valves are set for city water the pump is out of the system.

Rob

Second Chance wrote:

mobeewan wrote:
Doesn't matter what type of fresh water tank fill system that you have for your trailer, water can still leak past the pump internal check valve, filling the tank.

Not quite true. With our system, when all the valves are set for city water the pump is out of the system.

Rob

i have had travel trailer before, 2 to be exact and every time i connected to the city water connection , it never filled my fresh water tank.

Gdetrailer wrote:
Do you have a separate outside manual water fill?

If not, for RVs without the outside manual water fill they use a manual valve inside the RV to fill the water tank. That valve may be open slightly allowing water to slowly fill the tank.

If you do have outside manual water fill, the only way water can get into the fresh water tank is if the 12V water pump check valve fails..

In this case you need to check the hose on the input side of the pump (which goes to the freshwater tank) and see if there is water coming out of the input side of the pump with the city water pressurized.

If water pump check valve has failed, you might be able to get a rebuild kit or if you can't find parts you will need to buy a new water pump..

If you don't use freshwater tank at all and have no intentions to ever use it, you could add a manual shutoff valve on the output side of pump and simply turn off the valve.

On my trailer i have a Manuel freshwater with a cap, and a city water(screw type) connection. not following what you are trying to say here

Danford50 wrote:

Gdetrailer wrote:
Do you have a separate outside manual water fill?

If not, for RVs without the outside manual water fill they use a manual valve inside the RV to fill the water tank. That valve may be open slightly allowing water to slowly fill the tank.

If you do have outside manual water fill, the only way water can get into the fresh water tank is if the 12V water pump check valve fails..

In this case you need to check the hose on the input side of the pump (which goes to the freshwater tank) and see if there is water coming out of the input side of the pump with the city water pressurized.

If water pump check valve has failed, you might be able to get a rebuild kit or if you can't find parts you will need to buy a new water pump..

If you don't use freshwater tank at all and have no intentions to ever use it, you could add a manual shutoff valve on the output side of pump and simply turn off the valve.

On my trailer i have a Manuel freshwater with a cap, and a city water(screw type) connection. not following what you are trying to say here

Some RVs instead of having a gravity outside water fill will have a water fill valve inside the RV which allows you to open the valve with city water connected to fill the tank directly.

Since you have the outside gravity fill, you obviously do not have the internal water fill valve.

This means that your water pump has a bad check valve and is leaking water into the tank. That is the only way water can fill your tank without using the outside gravity fill.

You need to repair the pump or buy a new pump. Some pumps there may be a repair kit.

If you have no plans of using the fresh water tank, you could add a valve at the water pump and turn the valve off.

Second Chance wrote:

mobeewan wrote:
Doesn't matter what type of fresh water tank fill system that you have for your trailer, water can still leak past the pump internal check valve, filling the tank.

Not quite true. With our system, when all the valves are set for city water the pump is out of the system.

Rob

Do you actually have an extra valve that you shut off between the pump and the line from the city water inlet?

mobeewan wrote:

Second Chance wrote:

mobeewan wrote:
Doesn't matter what type of fresh water tank fill system that you have for your trailer, water can still leak past the pump internal check valve, filling the tank.

Not quite true. With our system, when all the valves are set for city water the pump is out of the system.

Rob

Do you actually have an extra valve that you shut off between the pump and the line from the city water inlet?

No extra value on the inside

Common everyday question asked on every RV forum it seems. Yes, most likely the check valve in the electric pump.

1) remove city water hose.
2) run pump extensively cycling faucets on and off.
3) turn pump OFF
4) reconnect city water hose and DO NOT touch the pump switch with city water connected.
5) wait a while and see if your problem is cured. This process usually clears the check valve of debris and reseats the check valve.

https://youtu.be/B_yI_tDcOxY

Charles

If the process Charles suggested doesn’t work, you can pretty easily take the pump apart and flush it out and manually unstick the check valve. On my trailer it’s harder to access the pump than it is to take it apart.