I don’t know why we didn’t do this sooner.
We’ve enjoyed boondocking for as long as we can ever since we hit the road in 2007. Early on, we discovered we can nearly double our freshwater capacity with collapsible water jugs. Getting that water into our freshwater tank, however, has always been a major hassle. Until now.
Watch this quick video and learn how to easily modify your RV plumbing system to use the water pump for filling the freshwater tank from any external source.
How To Modify RV Water Pump to Fill Freshwater Tank
Filling our freshwater tank from collapsible 5 gallon jugs was always a two-person job—we would both get wet, tired and frustrated. Never again.
By adding a few tee valve connectors to our water supply lines in the compartment with our pump, I am now able to easily and quickly add fresh water to our tank from any container, by myself, without getting in a fight.
The hardest part was figuring out where those valves should go. So here, I’ve done that for you.
NOTE: Our fifth wheel came with a tee-valve and tube intended for use when winterizing the rig. By turning the switch, the attached hose could be inserted into a jug of antifreeze. We never used that, though we sure should have at least once. But it was the inspiration for this mod I made!
1. Fill Tube
If your RV does not have a winterization bypass hose, you can easily insert a three way bypass valve in between the the input side of the pump and the freshwater tank, and attach a short length of flexible hose.
2. Bypass Valve
Insert another tee valve into the output hose coming from the pump to the pressurized water lines.
3. Redirect Valve
Finally, add a valve to redirect water back into the tank via the pressure relief hose on top.
4. Power Supply
Run wire from the nearest DC power source and splice it into the positive side of the pump’s power supply. Add a rocker switch so you can turn the pump on and off without shouting
at to someone inside the RV.
Tips for Modifying RV Water Pump to Fill Freshwater Tank
Measure carefully! Be sure to match your existing hose diameter to the new tee valve fittings and any extra hose you purchase.
Always use braided hose or Pex tubing for the pressurized side of your RV freshwater system. Clear PVC hose may be used for the input side, and is easier to curl and stow when not in use.
Spend a few extra cents and invest in high quality hose clamps.
WARNING: One of the weaker clamps I first used popped off a connection with a loud “pop” noise and instant running of the water pump. Luckily we were home! I immediately realized what had happened, shut off the pump and ran outside to clean up the mess that could have been much worse. Another reason to always shut off your RV water supply when you’re not home.
Secure hose clamps tightly using a wrench rather than screwdriver.
Turn off water pump at inside switch before operating new switch installed at pump.
Always open the freshwater supply inlet cap to prevent pressure build-up when filling tank.
Turn off switch at pump and remember to return tee valves to proper position for default functioning of freshwater system after filling tank.
Manual Alternative for filling RV Freshwater Tank from Jugs
If you want to get a workout and don’t mind getting a little wet, or you don’t feel like cutting into your RV’s freshwater plumbing, here is everything you’ll need to make a gadget like we used for years. Place the Water Bandit on a large mouth funnel and attach a fill tube. Have someone hold the funnel, hoist the collapsible 5 gallon jugs, and be patient!