How to Winterize an RV: Step-by-Step Guide
Cold weather is coming and I need to store my RV. How do I winterize the water system so the pipes, pump, and water heater don't freeze and crack?
Winterizing protects the parts that water can freeze and split: the fresh tank, lines, pump, water heater, and traps. The goal is to get all water out and either fill the lines with RV antifreeze or blow them out with air. The single most expensive mistake is leaving water in the water heater or lines over a hard freeze; the second is running RV antifreeze through the water heater (skip the heater by bypassing it). Plan an unhurried hour or two.
ℹ️ Reference only: For general reference only: AI-assisted and not professional advice. This guide guarantees no result; every situation differs. Verify against the manufacturer, local codes, and a licensed professional before acting, especially for electrical, gas, fuel, plumbing, structural, or roof work. Use at your own risk.
Common causes
- Water left in lines, pump, water heater, or low points freezes, expands, and cracks fittings, the pump head, or the tank. The damage shows up as leaks in spring. (the risk you're preventing) Quick check: If the rig will see temps below freezing and the water system still holds water, it's at risk. Winterizing removes that risk.
- Forgetting the water heater bypass: pumping pink RV antifreeze through a 6-10 gallon water heater wastes gallons of antifreeze and leaves residue. (common mistake) Quick check: Locate the water-heater bypass valves behind the heater's interior access. If you don't bypass, you'll dump antifreeze into the heater tank.
- Missing the low-point drains, traps, or exterior fixtures (outside shower, toilet, ice maker, washer), which then freeze. (common mistake) Quick check: Check your rig for low-point drain valves and every fixture that holds water: P-traps, toilet, outside shower, ice maker, and any washing machine.
How to fix it
- Drain the fresh water: empty the fresh tank, then open the hot and cold low-point drains and all faucets to let the lines drain. Drain and flush the gray and black tanks.
- Drain the water heater: turn it off and let it cool and lose pressure, then remove the drain plug/anode and open its pressure-relief valve to empty it. Never drain a hot or pressurized heater.
- Bypass the water heater using its bypass valves so you don't pump antifreeze into it.
- Method A (antifreeze): connect a hand or the onboard pump to a jug of NON-TOXIC RV (pink) antifreeze via the winterizing inlet/siphon. Pump it through each faucet (hot then cold), the shower, outside shower, and toilet until pink runs out of each. Pour a cup into each drain trap and the toilet bowl.
- Method B (blow-out): instead of antifreeze, use a blow-out plug and regulated compressed air (~30-40 psi max) to push water out of each line; many owners still add pink antifreeze to traps.
- Don't forget extras: ice maker, washing machine, exterior shower, and any water filter (remove/bypass cartridges).
- Label the rig 'winterized,' and in spring flush thoroughly and sanitize the fresh system before use.
DIY or call a pro?
Fully DIY for most owners. Winterizing needs only antifreeze or an air compressor, a few valves, and an hour. Have a dealer do it if you're unsure where your bypass valves, low-point drains, or winterizing inlet are, if your rig has complex systems (washer, ice maker, multiple water heaters, hydronic heat), or if you simply prefer it done with a warranty. Learning it once, though, saves a yearly service fee.
Tools & parts
- 2-3 gallons non-toxic RV (pink) antifreeze, OR a blow-out plug + air compressor
- Water-heater bypass kit (if not already installed) and a socket/wrench for the drain plug/anode
- Hand pump or use the onboard pump with a winterizing siphon
- Basic wrenches and screwdriver
- Eye protection
Keep a record of every fix you make: what broke, what it cost, how you solved it.
Track your RV's fixes in Garage Story →Based on: RV manufacturer and dealer winterizing procedures (water-heater bypass, low-point drains, antifreeze vs. blow-out); RV antifreeze manufacturer guidance (non-toxic pink, potable-safe use); General RV-owner guidance on spring de-winterizing and fresh-system sanitizing
General guidance only. Procedures vary by rig; follow your owner's manual, use only non-toxic RV antifreeze, and consult a dealer for complex water systems. Information here is general reference only and may be estimated or AI-assisted. It is not professional advice. Verify with a qualified professional before acting, and use it at your own risk. See our Terms & Disclaimer.