RV Water Pump Leaking When Connected to City Water? Do This!

When connected to city water, the pressure from the municipal water system will push the water through your RV’s plumbing system.

In this situation, your RV water pump is not used.

So, why then might your water pump start leaking when connected to city water?

Let’s explore some common causes for a leaky RV water pump when using city water and how to fix it.

Why Is My RV Water Pump Leaking?

If your RV water pump is leaking when connected to city water, the issue is most likely either in a connection to the water pump or in the water pump itself. Carefully examine where the leak is coming from, as this can mean the difference between a simple fix and full pump replacement.

Related: RV Water Pump Keeps Running? Do This!

Once you’ve identified the exact source of the leak, continue below.

Leak Is in a Connection to the Water Pump

If the leak is in a connection to the pump, then simply:

  1. Tighten the water hose connected to the water pump and, if applicable, check and replace the gasket.
  2. Dry the area.
  3. Keep an eye on the connection and around the water pump for any additional leaking.

Tip: If it’s still leaking, be sure the leak is actually coming from the connection. Even if the leak is coming from the housing, for example, it could run down to the water line connector and appear as if it’s a connection leak.

But why would the water pump leak at all when on city water?

In most RV plumbing setups, the city water inlet line is tied into the water pump’s outlet line since both lines feed the recreational vehicle with water. So, even though you are on city water, that water still hits the water pump where a check valve in the pump prevents backflow into the freshwater tank.

Tip: Use a water pressure regulator to protect your plumbing system from the excessive pressure that can come from city water systems. This will help prevent connection leaks and other plumbing system damage from occurring.

This diagram shows an example plumbing system in an RV, 5th wheel, or the like.

RV plumbing system diagram
RV plumbing system diagram

If the leak is from the water pump itself, then we have a few options.

Leak Is Coming From the Water Pump Housing

If water is coming out of the water pump itself, for example, through a seam or crack in the housing, you likely have a pump failure.

Before cracking the water pump open and attempting to fix it, check if the pump is still under warranty! If it is still under warranty and you mess with the pump and take it apart, that will likely void the warranty, and you’ll be forced to buy a new pump.

If it is under warranty, check with the warranty issuer for the next steps. Sometimes, you will have to buy a new pump out-of-pocket, send in the old pump for inspection, and if approved, you’ll get your money back. But, the process can vary depending on who the warranty is through.

If it’s not under warranty, should you attempt to fix it yourself? Unless you’re extremely handy and have experience repairing water pumps, we discourage this.

Not only could the pump go out again on the road, but a water pump leak can also cause a tremendous amount of damage that will be costly to fix.

Your best bet is to replace the old RV water pump with a new one. No matter your skill level, you can replace an RV water pump yourself with little cost. Check out our RV water pump replacement guide which will have you up and running again in 12 easy steps (and for less than $100).

If you do go the replacement route, be sure to use a quality water pump with a solid warranty, like a Shurflo RV water pump. Shurflo is a popular brand with great customer ratings, and they are very inexpensive!

Shurflo RV Water Pump 12v (3.5 GPM, 45 Psi)

Shurflo RV Water Pump 12v (3.5 GPM, 45 Psi)

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