How to Winterize Your RV: A Complete DIY Guide

The first winter we owned our camper van, we didn't winterize it. The result? Two burst water lines, a cracked water pump housing, and an $800 repair bill. Winterizing takes about 2 hours and costs less than $20 in supplies. Here's exactly how to do it, step by step.

When to Winterize

Winterize your RV when nighttime temperatures consistently drop below 32 degrees Fahrenheit (0 Celsius). In most of the northern US, this means late October to early November. If you're in the South, you might not need to winterize at all unless you're storing the RV in an unheated garage or it's a particularly cold year.

What You'll Need

• 2-3 gallons of RV antifreeze (pink, non-toxic, about $5/gallon)
• Water heater bypass kit (usually already installed on newer RVs)
• A hand pump or water pump converter kit ($15-20)
• Basic tools (screwdriver, pliers)
• Air compressor with blowout adapter (optional but helpful)

Step 1: Drain the Fresh Water System

Start by draining everything. Open the low-point drain valves under your RV (there are usually two, one for hot water lines and one for cold). Open all faucets inside, including the kitchen, bathroom, and outdoor shower. Flush the toilet to drain the bowl. Turn on the water pump briefly to push out any remaining water, then turn it off.

Step 2: Bypass and Drain the Water Heater

Your water heater holds 6-10 gallons of water. Turn off the water heater and let it cool completely. Open the drain plug on the outside of the water heater to drain it. If your RV has a water heater bypass kit (most do), activate it. This prevents antifreeze from filling the water heater, saving you 2-3 gallons of antifreeze.

Step 3: Blow Out the Lines (Optional but Recommended)

Using an air compressor with a blowout adapter, connect to your city water inlet and push air through the system at 30-40 PSI. Open each faucet one at a time until only air comes out. This removes most of the remaining water. Some people skip this step and rely solely on antifreeze, which works fine, but blowing out the lines first provides double protection.

Step 4: Pump Antifreeze Through the System

This is the core of winterization. Connect your hand pump or converter kit to the intake side of your RV's water pump. Put the intake hose into a gallon of RV antifreeze. Turn on the water pump. One by one, open each faucet (hot and cold sides) until you see pink antifreeze flowing. Then close it and move to the next one.

Don't forget these often-missed spots:

• The shower head
• The outdoor shower (if you have one)
• The toilet valve (hold flush lever until pink appears)
• The ice maker line (if equipped)
• The washing machine hookups (if equipped)

Step 5: Holding Tanks

Dump and rinse both black and gray holding tanks. Pour a quart of RV antifreeze down each drain (kitchen, bathroom, shower) to protect the P-traps. Pour a cup of antifreeze into the toilet bowl. This prevents any residual water in the drain lines from freezing.

Step 6: Battery Care

If you're storing your RV for the winter, disconnect the batteries. Cold weather drains batteries, and a fully discharged battery can freeze and crack. The best approach is to remove the batteries entirely and store them in a garage or basement. Keep them on a trickle charger or maintainer to keep them at full charge through winter.

If you have lithium batteries, they're more cold-tolerant but should still be stored above 32 degrees Fahrenheit if possible. Never charge lithium batteries below freezing since it can permanently damage the cells.

Step 7: Tires and Exterior

Inflate tires to the maximum PSI listed on the sidewall (not the placard pressure, which is for driving). If storing for more than a month, consider using tire covers to protect against UV damage and flat spotting. If possible, move the RV slightly every 30 days to prevent flat spots.

Wash the exterior, clean the roof, and check all seals around windows, doors, and roof penetrations. Seal any cracks with Dicor self-leveling sealant. Water that enters through cracked seals will freeze, expand, and cause delamination, which is one of the most expensive RV repairs.

Spring De-Winterization

When spring arrives, the process reverses. Flush your water system by connecting to city water and running each faucet until the pink antifreeze clears and you see clean water. Sanitize the system with a quarter cup of household bleach per 15 gallons of tank capacity. Fill the fresh tank, run bleach water through every faucet, let it sit for 12 hours, then flush thoroughly with fresh water. Reconnect batteries, check tire pressure, and you're road-ready.

The 2 hours you spend winterizing saves hundreds in potential repairs and gives you peace of mind all winter. Add it to your calendar so you never forget.