How to Blow Out RV Water Lines with Air

Winterizing your RV is an essential step to prepare it for the cold season. One vital part of winterizing is blowing out your RV’s water lines to prevent any residual water from freezing and causing damage. Blowing out your RV water lines with air is a relatively straightforward process, but it does require some attention to detail and proper technique.
In this guide, we will outline the necessary steps to blow out your RV water lines with air, ensuring they are properly winterized and protected from potential freezing damage.
1. Gather the necessary tools and materials:
Before blowing out your RV’s water lines, you’ll need to gather several essential tools and materials:
– An air compressor capable of delivering at least 30 psi (pounds per square inch)
– A dedicated blowout plug (standard size: 1/4-inch male pipe thread)
– Adjustable wrench
– Safety goggles
2. Drain the water from your RV’s tanks and appliances:
Before blowing out the water lines, ensure you have drained all excess water from your freshwater tank, grey tank, black tank, and all appliances connected to the plumbing system.
3. Turn off all faucets and electrical appliances:
Close all taps inside your RV. Be sure to turn off any electrically powered devices that connect to the plumbing system, such as your hot water heater or demineralizer, as a precautionary measure.
4. Attach a blowout plug/adapter to your City Water Inlet:
Locate your RV’s city water inlet, which is typically found on the driver’s side or rear wall of the vehicle. Remove any protective cap and attach the blowout plug firmly using an adjustable wrench.
5. Set up the air compressor:
Ensure that your air compressor can deliver air pressure between 30 – 50 psi. Set it at 30 psi initially and do not exceed 50 psi as over-pressurization can damage your water lines or plumbing fixtures.
6. Connect the air compressor to the blowout plug:
Securely connect the air hose from your compressor to the blowout plug. Double-check all connections before proceeding.
7. Turn on the air compressor:
Put on safety goggles and turn on your air compressor. Allow it to fill with air until it reaches your desired pressure.
8. Blow out RV water lines:
Start with the fixture closest to your city water inlet, and slowly open each faucet as you progress through your RV. You should hear the sound of air escaping from each opened faucet. Continue until there is no longer any water coming out of any of the faucets—only air should be released at this point.
9. Repeat the process (optional):
Repeat steps 7 – 8 for a thorough cleaning, this time slightly increasing air pressure up to, but not exceeding, 50 psi. This may help loosen any stubborn debris within the lines.
10. Disconnect and wrap up:
Once all water lines have been blown out with air, disconnect your air compressor and remove the blowout plug from your city water inlet. Replace any protective caps or covers in place.
Now that you’ve successfully blown out your RV’s water lines with air, they are ready to endure winter’s freezing temperatures without risk of damage from ice expansion. Store your RV confidently, knowing it will be in excellent condition when it’s time for your next adventure!