RV Water Pump Leaking When Connected to City Water?

Modern RVs provide all sorts of amenities people need to spend their time out on the camping grounds or out in the wilderness. However, behind the vast array of features lies a complex system that ensures your comfort throughout your vacation. One main system is the plumbing system that regulates water through an RV. Its importance cannot be undermined as a small fault in it can lead to a major disruption in your planned travel schedule.

Speaking of disruptions in the plumbing system of a camper van, one major problem is water leakage through or close to the water pump when the system is connected to city water. There are a variety of ways to approach this problem and all of them have been addressed below:

The Faulty Check Valve

Water pump leaking when connected to city water may sound bizarre since the valve is turned to the city position and apparently the pump hasn’t got anything to do when the city water is connected. However, the thing is both the water pump outlet and the city water inlet are connected to each other inside the water pump. A check valve is built into the pump to prevent backflow through it. So, in almost every case of the water pump leaking when connected to the city water, it is actually the check valve in it that has given up. This practice of tying up the water pump outlet together with the city water inlet makes the process easier and cheaper for the manufacturers. Though, it causes inconvenience for the RVers by making the system prone to leakage when connected to the city water supply.

One straightforward solution to this is to just replace the water pump. The other not-so-straightforward solution is to see if something has stuck in the check valve. Sometimes taking the pump’s head apart and clearing the blockage works. See if does in your case as well.

In some instances, replacement pump head and check valve can be sourced from the market if their part/serial number can be confirmed from the manual. If both of these solutions aren’t possible then replacing the pump is the only solution.

Installing a shutoff valve to the output of the water pump is a good way to minimize the water overflow/leakage when the city water is connected. This would prevent the leaking water to fill up the fresh water tank and cause a burst of overflowing water. This won’t address the leakage issue but will allow you to control the overflow from the top.

An Alternative Approach

Another way to pinpoint water leakage through a water pump is to listen whether or not the pump stops pumping whenever you are done using the toilet or a faucet. If the pump continues to operate even after completing tasks, then there is a good chance that leakage is present in or around it. The leakage is prompting the pump to continue pumping water afterward. The prime culprit in such a situation is also a broken check valve. A cracked check valve tells the pump to keep pumping which leads to water leakage.

Again, the remedy to this problem is to either replace the pump head and check the valve or replace the water pump. However, if the replacements aren’t available then installing a new pump is the only solution. But before you begin to change the pump, start by turning off the water supply. Nowadays, water pumps are treated as a disposal item and mostly their spares aren’t sold separately. Sometimes even the OEM pump isn’t available, and you would have to go with a pump that is closely related to the specs of the OEM one. While connecting ensure that all connections are wrapped with Teflon tape. Once connected, make the connection snug so they don’t lead to a leak in the future.

A Pipe Leakage

Often it is not the water pump but a pipe leakage that is mistaken as a pump leakage issue. To differentiate between the two, completely wipe off the water and then notice where the water droplets are coming from. If it is a connection to the pump, then open it up and install a new gasket and make a good seal with Teflon tape around it. Afterward, connect it to the pump and tighten it firmly and observe again if the leakage has been rectified.

High-Pressure City Water

City water is often highly pressurized which puts the RV plumbing system under increased load leading to leakages from joints that are often misconstrued as water pump leakage. It has been established that the campground water pressure is often close to 100 PSI which is well above the safe limit of 40-50 PSI. Installing a pressure regulator in your water line or reducing the pressure from the source is a good way to tone down the high-pressure city water supply.

City Water Inlet Leakage

Aside from water pump leakage on city water, there are some instances when a city water inlet starts leaking water. The most common cause is high-pressure water which can be taken care of by toning down the pressure or by installing a pressure regulator as mentioned above.

The other cause includes a bent hose which leads to a deformed seal ultimately causing a leak. A careful inspection can highlight this issue and the solution is also rather straightforward. Simply turning the water hose to change the direction of the bend can temporarily get rid of the water inlet leak. For a better solution, it is advised to replace the freshwater hose.

Bad gaskets aren’t only a cause for leakage around the pump connections, but they can also lead to water leakage around the inlet. To confirm whether it’s a bad gasket causing the issue, remove the water hose and check if the gasket is torn up or in bad shape. If it is the gasket, then you will need to replace it. Replacement gaskets are easily available, though try to get a silicone gasket as they generally last longer than rubber ones. Purchase some extra gaskets while you are at it as they can come in handy in the future.


Some signs that your RV water pump needs to be replaced include decreased water pressure, strange noises coming from the pump, and leaks. If you notice any of these issues, it's best to take your RV to a qualified technician for diagnosis and repair. Trying to fix the problem yourself could make it worse, so it's always best to leave it to the professionals.

We do not recommend replacing your RV water pump yourself. Servicing and repairing an RV water pump is best left to qualified technicians. Trying to fix the problem yourself could make it worse, so it's always best to leave it to the professionals.


+ posts

Ever since I was a kid, I've been fascinated by travel. I inherited this passion from my parents. Since my college years and to this day, I have had a passion for traveling in a motorhome. I am here to share my experiences with you.

We will be happy to hear your thoughts

Leave a reply

RV Camp Gear
Enable registration in settings - general