Quick Summary
Winterizing your RV helps protect the plumbing system, water heater, faucets, toilets, pumps, and appliances from costly freeze damage during cold weather. Whether you use compressed air, RV antifreeze, or a combination of both, taking the time to winterize your RV properly can save you from expensive repairs next spring.
⚠️ Safety Stop
Before beginning, disconnect the RV from city water and turn off the water heater. Allow the water heater to cool completely before draining it.
Freeze damage can occur if even a small amount of water remains trapped inside plumbing or appliances. Every RV is slightly different, so always follow your manufacturer’s recommendations if they differ from this guide.
This article is provided for general educational purposes. Because every RV is different, Last Mountain Tech cannot guarantee results or accept responsibility for damage resulting from improper winterization or misuse of this information.
Should You Winterize It Yourself?
Many RV owners successfully winterize their RV every fall. However, it isn’t always the best option.
Consider hiring a professional if:
- This is your first time winterizing an RV.
- You’re unsure whether your RV uses a water heater bypass.
- You don’t know where the low-point drains are.
- Your RV has a residential refrigerator, washer, dishwasher, or other specialty plumbing.
- You simply want peace of mind before winter arrives.
Professional winterization often includes:
- Complete plumbing system draining
- Water heater bypass installation (if needed)
- Pump and plumbing protection
- Appliance winterization
- Leak inspection
- Documentation of completed work
Many dealerships and RV service centers also guarantee their winterization service. Ask what their warranty or guarantee covers before booking an appointment.
While winterizing your RV yourself can save money, repairing freeze damage often costs far more than professional winterization.
Tools & Supplies You’ll Need
Gather everything before you begin.
Recommended supplies include:
- 2–4 gallons of non-toxic RV/Marine antifreeze (amount varies by RV size and method)
- Water heater bypass kit (if not already installed)
- Water pump winterizing kit (optional but helpful)
- Air compressor with pressure regulator (if using the blow-out method)
- Blow-out plug
- Screwdrivers
- Adjustable wrench or socket set
- Bucket
- Towels or rags
- Owner’s manual
Never use automotive antifreeze in your RV’s fresh water system.
How to Winterize Your RV
Step 1: Empty the Holding Tanks
Completely empty the:
- Black tank
- Gray tank
- Fresh water tank
Flush each tank thoroughly if possible.
Step 2: Drain the Water Heater
Turn the water heater off and allow it to cool.
Open the pressure relief valve to relieve the pressure in the tank (failure to do so may cause injury)
Remove the drain plug or anode rod and allow the tank to drain completely.
Leave the pressure relief valve open if necessary to speed draining.
Step 3: Bypass the Water Heater
If your RV has a bypass valve, place it in the bypass position.
This prevents filling the water heater with several gallons of antifreeze unnecessarily.
Step 4: Open the Low-Point Drains
Open both the hot and cold low-point drains.
Allow as much water as possible to drain from the plumbing system.
Close the drains after the system has finished draining.
Step 5: Blow Out the Plumbing (Optional but Recommended)
Many RV owners first blow out the plumbing before adding antifreeze.
Using regulated compressed air (typically 30–40 PSI maximum), open each faucet one at a time until only air comes out.
Don’t forget:
- Kitchen sink
- Bathroom sink
- Shower
- Outdoor shower
- Toilet
- Washer hookups
- Ice maker line (if equipped)
Step 6: Pump RV Antifreeze Through the Plumbing
Using the RV water pump or winterizing kit, pump non-toxic RV antifreeze throughout the plumbing.
Open each fixture until pink antifreeze appears.
Do both:
- Hot side
- Cold side
Repeat for every faucet and appliance.
Step 7: Protect Drains and Holding Tanks
Pour a small amount of RV antifreeze into:
- Every sink drain
- Shower drain
- Toilet bowl
- Toilet flush valve
This protects the P-traps and valves from freezing.
Step 8: Final Inspection
Before storing your RV:
- Verify water heater remains bypassed.
- Ensure all drains are closed.
- Check for forgotten faucets.
- Remove water filters if applicable.
- Store hoses separately.
- Leave cabinet doors open where plumbing is hidden if storing in very cold climates.
Download the Complete RV Winterization Checklist
Want a printable checklist you can take with you?
Download the complete RV Winterization Checklist, including:
- Printable step-by-step checklist
- Tool and supply checklist
- Appliance checklist
- Common mistakes to avoid
- Spring de-winterization reminder
- Maintenance notes
👉 Download the checklist here.
Frequently Asked Questions
Should I use compressed air or RV antifreeze?
Many RV owners use both. Blowing out the lines removes most of the water, while RV antifreeze protects any remaining water trapped in the plumbing.
How much RV antifreeze do I need?
Most travel trailers and fifth wheels require approximately 2–4 gallons, depending on the plumbing layout and whether you’re using the blow-out method first.
Can I use automotive antifreeze?
No.
Automotive antifreeze is toxic and should never be introduced into an RV’s fresh water system.
Only use non-toxic RV/Marine antifreeze designed for potable water systems.
Do I need to winterize if my RV is stored indoors?
If the storage building is heated and guaranteed to remain above freezing, winterization may not be necessary.
If temperatures could fall below freezing—even briefly—it’s safest to winterize the RV.
When should I winterize my RV?
Complete the process before the first hard freeze in your area. Waiting until freezing temperatures arrive increases the risk of damaged pipes, fittings, water pumps, and appliances.
Written by Dan Harvickson (Founder of Last Mountain Tech) RV Specialist