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How do I winterize my van's plumbing system?

Updated: Jun 25, 2023

Winterizing your van's plumbing system is an important step to take to protect it from the potential damage caused by freezing temperatures. The reason for this is that any water left in the plumbing system can freeze and expand, potentially causing damage to the pipes, valves, and fittings. This can lead to leaks and other costly repairs that can be avoided by properly winterizing the plumbing system. If you're planning to store your van or use it in an area where temperatures can drop below freezing (and can't leave the heat on all the time), it's essential to winterize the plumbing system to prevent costly repairs. Even if you think you won't be using the plumbing system during the winter, it's still important to winterize it to prevent any potential damage. It's better to be safe than sorry when it comes to protecting your van's plumbing system from the elements. In this guide, we'll provide you with detailed instructions on how to winterize your van's plumbing system.



Step 1: Drain the Water System


The first step to winterizing your van's plumbing system is to drain all the water from the system. If you have drain valves on your gray and freshwater tanks, open each to release any standing water. Then continue by turning on the water pump and opening all the faucets and valves, including the hot water faucet, the cold water faucet, and the showerhead if you have one. Leave the faucets and valves open until all the water has drained out. Next, remove the drain plug (if you have one) from the water heater and allow it to drain completely. Once all the water has drained out, replace the drain plug and any removed on the tanks.


Step 2: Clear Out the Water Lines


After draining all the water from the system, you need to attempt to clear out any remaining water in the lines and tanks. There will likely be some lying at the low points of piping, no matter how strong your pump is. At the very least, fragments of water will remain in the pump, accumulator, filters, etc. which can build up and result in mildew/mold even if they don't freeze. There are several ways to do this, but one of the most effective methods is to use compressed air. You'll need an air compressor and a blowout plug that fits the water inlet on your van.


First, attach the blowout plug to the water inlet on your van. Next, connect the air compressor to the blowout plug and turn it on. Open all the faucets and valves one by one, starting with the furthest one from the water inlet. Allow the compressed air to blow through each line until no more water comes out. Not everyone is able to do this step, and if you can't, then be sure to be diligent with step #3. If you're regularly storing your van for winter or for a long period, it's worthwile to get in the practice of clearing out lines thoroughly.


Step 3: Add Antifreeze


Once you've drained all the water and cleared out the lines, it's time to add antifreeze to the system. Antifreeze helps to protect the plumbing system from freezing by lowering the freezing point of the water. You'll need to purchase a non-toxic RV antifreeze for this step.


Start by pouring a small amount of antifreeze into the sink drain and the shower drain. This will help to protect the traps from freezing. Next, pour antifreeze into the fresh water tank until it's about a quarter full. Turn on the water pump and open each faucet and valve, one at a time, until you see the pink antifreeze coming out. Keep the faucets and valves open until you see a steady flow of antifreeze. When you return to use the van after storing and winterizing, you'll of course need to flush any antifreeze deposited into the water system as you're not supposed to drink it.


Step 4: Drain the Water Heater


After adding antifreeze to the system, you'll need to drain the water heater again. This time, you're draining the water that's mixed with antifreeze. To do this, remove the drain plug from the water heater and let it drain completely. Once all the water and antifreeze have drained out, replace the drain plug.


Step 5: Seal the Water Inlet


The final step is to seal the water inlet to prevent any water, condensation or debris from getting into the plumbing system. You can use a threaded plug or a blowout plug to seal the water inlet. If you're using a threaded plug, make sure it's tight and secure. If you're using a blowout plug, make sure it's screwed in tightly.


In conclusion, winterizing your van's plumbing system is an essential step to take to protect it from the potential damage caused by freezing temperatures. By following the steps outlined in this guide, you can ensure that your plumbing system is properly winterized and ready for the colder months ahead. Remember to always use non-toxic RV antifreeze, and to follow the manufacturer's instructions for your specific van model.


Where can I find first-hand answers related to winterizing my plumbing system?


Reddit is a great start:



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