How to Winterize a Camper - Protect Your RV Water System
A single hard freeze destroys RV plumbing. Cracked water lines, split fittings, a ruined water heater — repairs run $500-$2,000. Winterizing takes less than an hour and costs under $20 in antifreeze.
Two Methods
Method 1: Air Blowout
Uses compressed air to force water out of the lines. Faster but not as thorough — pockets of water can remain in low spots and valves.
Method 2: RV Antifreeze
Fills the entire system with non-toxic antifreeze. More thorough and the preferred method for extended storage.
Best approach: Combine both. Blow out the lines first, then push antifreeze through. Belt and suspenders.
What You Need
- 2-3 gallons RV/marine antifreeze (pink, non-toxic)
- Blowout plug (fits city water inlet)
- Air compressor (set to 30-40 PSI max)
- Basic tools for water heater drain plug
Step-by-Step: Full Winterization
1. Drain the Water Heater
Turn off the water heater and let it cool completely. Open the pressure relief valve on top, then remove the drain plug on the bottom. Let it drain fully.
Never blow compressed air through a full water heater. The pressure can damage the tank.
2. Bypass the Water Heater
Most RVs have a bypass kit — two valves that route water around the heater instead of through it. This saves you 6-10 gallons of antifreeze.
Turn the bypass valves to the “bypass” position. If your RV doesn’t have a bypass kit, install one. They cost $15 and take 20 minutes.
3. Drain All Water Lines
Open every faucet (hot and cold). Open the low-point drains (usually under the RV, one for hot, one for cold). Flush the toilet. Run the outdoor shower if equipped.
Let everything drain until water stops flowing.
4. Blow Out the Lines
Connect the blowout plug to the city water inlet. Set your compressor to 30-40 PSI — never exceed 45 PSI or you’ll damage fittings.
Open each faucet one at a time (hot then cold) until only air comes out. Flush the toilet until dry. Run the outdoor shower.
5. Add RV Antifreeze
Disconnect the inlet side of the water pump. Drop the hose into a gallon of RV antifreeze. Turn the pump on.
Open each faucet one at a time until pink antifreeze flows consistently. Start with the faucet closest to the pump and work outward:
- Kitchen faucet (hot then cold)
- Bathroom faucet (hot then cold)
- Shower (hot then cold)
- Toilet (flush until pink)
- Outdoor shower
- Ice maker supply line (if equipped)
6. Protect the Drains
Pour a cup of antifreeze down each drain — kitchen sink, bathroom sink, shower and toilet bowl. This protects the P-traps from freezing.
7. Close Everything Up
Close all faucets and low-point drains. Leave the water heater bypassed. Turn off the water pump. Disconnect from city water.
Spring De-Winterization
- Close bypass valves (water heater back in circuit)
- Reinstall water heater drain plug
- Connect to city water or fill the fresh tank
- Open each faucet and run until water runs clear (no pink)
- Flush the system with a few tank-fulls of fresh water
- Sanitize the system with a bleach solution (1/4 cup per 15 gallons)
Texas-Specific Tips
DFW winters are unpredictable. Some years barely freeze, others bring ice storms. If your camper sits outside between November and March, winterize it.
If you camp through winter with hookups, leave cabinet doors under sinks open so warm air reaches the pipes. A heat tape on exposed lines under the RV provides extra insurance.
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