A chilly night in Wise County can sneak up on you. If your RV is going into storage, draining the fresh-water tank is a good start. Water can still collect in fittings, valves, and low spots. When it freezes, it expands, and you may discover the damage only after you turn the water back on.
Blowing out the lines uses regulated compressed air to push out water that gravity leaves behind. Here’s how to plan the job before the first hard freeze.
Start with your RV’s manual
Check the winterizing instructions for your exact make and model. Some RVs can be winterized by blowing out the supply lines, while others call for RV plumbing antifreeze or a combination of both. Tankless water heaters, residential refrigerators with ice makers, and washers may have their own procedures.
If your manufacturer approves the blowout method, gather a blowout adapter for the city-water inlet, an air compressor with a regulator and gauge, and any drain tools or RV plumbing antifreeze your manual calls for.
Drain first, then clear the lines
Disconnect the water supply and drain the system. Follow your manual’s sequence for the fresh-water tank, low-point drains, and water pump. Shut off the water heater’s gas and electric power. Let a tank-style heater cool completely and relieve pressure as directed before opening its drain. Follow the heater’s own instructions for draining and bypassing it.
Connect the blowout adapter to the city-water inlet. Use clean, dry, regulated air and follow your model’s pressure limit. For example, Winnebago’s 2020 Minnie Winnie manual specifies 30 psi or less for its blowout procedure. Check your own manual before setting the regulator. Winnebago owner’s manual
Work through every fixture in your manual’s sequence. Clear the hot and cold sides of each faucet, the indoor and outdoor showers, and the toilet supply. Check any appliance or accessory lines separately. The outdoor shower is an easy one to miss, especially if you rarely use it.
Protect the drains and toilet as directed. Blowing out the supply lines can leave water in sink and shower traps. Follow your manual for where to add RV or marine plumbing antifreeze and how much to use. Use a product labeled for RV plumbing. Keep automotive antifreeze away from the freshwater system.
Staying in your RV through the freeze?
If you’ll be living in your rig and using the plumbing, make a cold-weather plan for your specific RV. Pay special attention to exposed hoses and connections, and check what your manufacturer recommends for keeping tanks and plumbing bays protected while the system is in use.
A quick walk-through before the temperature drops can save you from finding a cracked fitting the next time you hook up. At Mimosa Valley RV Park, we’d rather spend that first cold morning enjoying a hot cup of coffee than looking for a leak.
Disclosures
This post is general information from Mimosa Valley RV Park. Follow the winterization instructions for your RV and its individual appliances. If you’re unsure about your setup, consult a qualified RV technician. This post contains no affiliate links. The source article includes its own affiliate disclosure.
Source and further reading
Dave Helgeson, How to Blow Out RV Water Lines Using an Air Compressor, Do It Yourself RV
