Even experienced RVers will startle if they see their freshwater tank suddenly overflowing. The situation is particularly baffling when you’re hooked up to city water and not even using your vehicle’s freshwater tank. How does the tank fill up and overflow while you’re relying on city water? There are a few factors that might cause this issue. Learn more about why an RV freshwater tank will fill up unexpectedly and how to fix the problem with this overview.
Open or Faulty Valves
An open or faulty valve can cause water to flow backward through the pump and into your freshwater tank. Before doing anything drastic, check the quick fill valve and the check valve. Not all RVs have a quick fill valve, but ones that do will allow you to fill your freshwater tank while hooked up to the city water. If this valve gets stuck or broken—or you leave it in the on position—it will allow water to continuously flow into the freshwater tank, causing it to fill unexpectedly.
If the quick fill valve is fine (or if your RV doesn’t have one), inspect the check valve. This one-way valve prevents backflow in your RV. If it’s dislodged, stuck, or damaged, it will also allow the city water to flow backward into your freshwater tank. Fixing this issue might be a simple case of securing or cleaning out the valve so it can shut completely again. However, if you find damage to these valves, you might be able to replace just the valve instead of the entire water pump system.
High City Water Pressure
Water pressure is another reason why an RV freshwater tank will fill up unexpectedly. If the city water pressure is extremely high, it can lead to leaks and other issues with your pump and plumbing system. Use a water pressure regulator every time you connect your RV to an outside source. Even if the city water pressure is normal when you first connect your RV, other users hooking or unhooking their vehicles can cause it to fluctuate. A water pressure regulator keeps your RV’s water system safe while ensuring you have a comfortable flow of water during your trip.
Preventing Further Issues
In the best-case scenario, issues with your water tank are a minor annoyance. However, worst-case scenarios can cost you a lot of time and money while ruining your RV trip. Prevent these problems and keep your RV safe by following best practices every time you hook up your RV to city water. Check the campsite’s water pressure with a gauge and use a water pressure regulator. Take care of your vehicle’s water system by regularly checking the valves, pipes, and tanks for cracks, debris, and other damage. This vigilance is crucial no matter where you go or what season it is. In the summer, keep an eye out for leaks and other issues. In the winter, protect your system with RV holding tank heaters and other winterization products. UltraHeat heating pads for your tanks, valves, and pipes will prevent freezing in your system, saving your plumbing from clogs, cracks, and other costly issues.