Winterizing an RV wrong — or skipping it — is one of the most reliable ways to write yourself a $1,500–$3,000 repair bill in the spring. Here's the complete process in order. Do every step.
Winterizing an RV wrong — or skipping it entirely — is one of the most reliable ways to write yourself a $1,500–$3,000 repair bill in the spring. Frozen water lines crack. Burst tanks split. Water heater elements corrode. And unlike a soft floor that develops slowly, freeze damage announces itself all at once when you turn the pump on for the first time in March.
Here's the complete process, in order. Do every step.
When to Winterize in Northern California
Redding sits at 500 feet elevation and rarely freezes hard, but the surrounding areas are a different story. Anderson, Shasta Lake, Red Bluff, and the foothill corridors can see overnight lows in the mid-20s from November through February. If your RV is stored outdoors anywhere in Northern California and temps drop below 32°F at night — even occasionally — winterize it.
If you're in the Mt. Shasta, Weed, or higher-elevation areas, winterize by late October without question.
What You Need
- Non-toxic RV antifreeze (pink) — 2–4 gallons depending on your rig's plumbing layout
- Water pump converter kit (or hand pump to push antifreeze through lines)
- Basic tools: screwdriver, wrench, flashlight
- Compressed air (optional — for blow-out method)
- Moisture absorber packets for interior (DampRid or equivalent)
Step 1: Drain All Water From the System
Drain the fresh water tank completely
Open the fresh tank drain valve — usually a petcock on the underside of the tank. Let it drain fully. If you've been running city water hookup, nothing will be in the fresh tank, but drain it anyway to confirm.
Drain the water heater
Turn the water heater off and let it cool completely (at least 2 hours after last use — hot water + cold air = cracked element). Remove the drain plug or open the pressure relief valve to drain. Skip this step and your water heater element or tank may crack when temps drop. This is the most commonly skipped step and the most expensive consequence.
Open all low-point drains
Your RV has low-point drain valves — typically two (hot and cold) — on the underside of the rig at the lowest plumbing point. Open both and let water drain out. Leave them open until you're done with the antifreeze step.
Open every faucet — hot and cold
Run the pump briefly to push remaining water out of the lines, then turn the pump off. Leave the faucets open while you work through the rest of the steps.
Flush the toilet to empty the valve
Hold the flush pedal down for 10–15 seconds to clear water from the toilet valve mechanism.
Step 2: Bypass the Water Heater
Before adding antifreeze, bypass the water heater. Your water heater tank holds 6–10 gallons — without bypassing it, you'll fill that tank with antifreeze instead of running it through the lines. Most modern RVs have a bypass kit already installed (three valves at the back of the water heater). If yours doesn't, it's a $15 kit and a 20-minute install.
- Close the cold inlet valve to the water heater
- Close the hot outlet valve from the water heater
- Open the bypass valve that connects inlet directly to outlet
- Confirm: antifreeze will now flow through the bypass, not into the heater tank
Step 3: Add Antifreeze Through the Lines
The easiest method for most owners is the water pump converter kit: a hose that plugs into the pump inlet and draws directly from an antifreeze jug instead of the fresh tank.
Connect the pump to the antifreeze jug
Install the converter hose on the pump inlet, place the pickup tube in a full gallon of pink RV antifreeze.
Turn on the pump and open one faucet at a time
Start at the faucet closest to the pump. Run it until pink antifreeze flows steadily, then close it. Move to the next faucet. Do every hot and cold line — sinks, shower, outdoor shower if equipped.
Flush the toilet until pink appears
Hold the pedal and let antifreeze flow through the toilet valve until you see pink water in the bowl.
Pour antifreeze into every drain
P-traps hold water and will freeze. Pour about a cup of antifreeze down every sink drain, the shower drain, and the toilet. This protects the trap water.
Close all low-point drains
Now that antifreeze is in the lines, close the low-point drains you opened in Step 1.
How much antifreeze?
A typical Class C or travel trailer uses 2–3 gallons. A large Class A with multiple bathrooms and an outdoor kitchen can use 4–5 gallons. Buy an extra jug — running out with half the lines done is worse than having a gallon left over.
Step 4: Protect the Rest of the Rig
- Disconnect and store the battery if the rig will sit for more than 4–6 weeks — or connect a battery tender to prevent sulfation
- Remove all food, even canned goods — freezing damages cans and attracts pests
- Place DampRid or moisture absorbers inside to prevent mildew buildup
- Cover roof vents to prevent rain and critter entry, but leave some ventilation
- Remove or stabilize propane — tanks can stay on; regulators and lines need a visual inspection in spring
- Check tire pressure before storage — cold weather drops pressure roughly 1 PSI per 10°F of temperature drop
- Place steel wool or copper mesh around any openings where rodents could enter (water lines, cable pass-throughs)
Spring De-Winterization Checklist
- Reinstall water heater drain plug and close pressure relief valve before filling system
- Remove water heater bypass — restore normal hot/cold flow through the heater
- Open all low-point drains briefly to flush any antifreeze that settled there
- Connect to city water or fill fresh tank and run every faucet until clear water flows — no more pink
- Flush toilet multiple times until water runs clear
- Check all exterior seals and lap sealant before first use — winter temperature changes stress seals
- Test smoke detector, CO detector, and propane detector batteries
Common Question
Do I need to winterize my RV in Northern California?
Yes, if temps drop below freezing at your storage location — even occasionally. Redding proper rarely freezes hard, but surrounding areas including Anderson, Shasta Lake, Red Bluff, and the foothill corridors regularly see sub-freezing overnight lows from November through February. Higher elevations (Mt. Shasta, Weed) should winterize by late October.
Common Question
How much does it cost to have an RV winterized professionally?
Professional winterization by a mobile tech in Northern California typically runs $120–$200 depending on rig size and system complexity. That includes antifreeze, labor, and a basic systems check. Given what freeze damage costs to repair, it's one of the better-value services we offer.
Common Question
Can I winterize my RV myself?
Yes — the process is straightforward if you're comfortable following steps and have the right materials. The water pump converter kit makes the antifreeze step easy. The most commonly skipped step (and the most expensive to skip) is draining and bypassing the water heater. Don't skip it.
If you'd rather have it done right the first time, we winterize RVs on-site throughout Redding and all of Northern California. Learn about our RV plumbing and winterization service.
BossBros RV Team
Redding, CA