How to Winterize Your RV Plumbing System

When freezing temperatures hit, your RV’s plumbing system is especially vulnerable. Even a small amount of water left in the lines can freeze, expand, and crack pipes or fittings. Learning how to winterize your RV plumbing system protects your rig from costly damage and ensures it’s ready for spring.

Why RV Plumbing Needs Winter Protection

Unlike a home, your RV’s pipes are more exposed and often routed through compartments that lack insulation. When water freezes inside:

Plastic pipes can crack
Fittings can loosen or burst
Water pumps and valves can be damaged
Repairs can be expensive and labor-intensive

Proper winterization is especially important if your RV is stored outdoors or unused for long periods. Daisy RV offers full winterization packages if you want help doing it right.

1. Drain All Water Tanks

Empty the fresh water, gray water, and black water tanks
Rinse the black tank thoroughly with a tank wand or flush system
Remove drain plugs and low-point drains to empty the system completely

2. Bypass the Water Heater

Use the built-in water heater bypass valve (or install one if needed)
This prevents antifreeze from filling the heater tank unnecessarily

3. Drain the Water Heater

Turn off heat sources and allow the water to cool
Remove the drain plug or anode rod
Open the pressure relief valve to ensure full drainage

4. Blow Out the Water Lines (Optional but Recommended)

Connect an air compressor to the city water inlet using an RV blowout plug
Set compressor to 30–50 PSI max
Open each faucet (hot and cold) one at a time until no water comes out
Don’t forget outside showers, toilet, and low-point drains

5. Add RV Antifreeze to Plumbing

Use only non-toxic pink RV antifreeze (never automotive)
Connect a siphon hose to the water pump inlet or use a hand pump at the city inlet
Run the pump and open faucets one by one until pink antifreeze flows out
Flush the toilet until antifreeze fills the bowl
Pour antifreeze down each drain trap to protect P-traps

6. Protect the Water Pump

Run antifreeze through the pump
Turn off the pump and relieve pressure
Some models have a filter—empty and clean it as well

Need the right antifreeze or tools? Visit Daisy RV or schedule a full winterization service today.

Final Winterization Tips

Remove any inline water filters—they can be damaged by antifreeze
Label the system clearly so you remember to flush it in spring
Store your RV with the faucets closed but system depressurized
Check for leaks around fittings after filling with antifreeze

A Frozen Pipe Can Cost You Hundreds

Taking a little time to learn how to winterize your RV plumbing system saves you from the headache and expense of broken lines, flooded compartments, or ruined water pumps. Make it a seasonal habit or let a pro do it for peace of mind.

Why RV Plumbing Needs Winter Protection