The Trailer Owner's
Complete Field Guide
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M2

Winterization

Protect your trailer from freeze damage before the first cold snap. Strong recommendation: have a professional do this if you're new to your trailer.

⏱ 2–3 hours active

Freezing water in your RV lines doesn't just crack pipes — it damages pumps, water heaters, and tank sensors in ways that don't always show up until your first spring trip. Winterization takes about 90 minutes if you have materials staged. This checklist covers the antifreeze method with the bypass valve steps that prevent you from pumping antifreeze into your fresh tank.

⚠ Strong Recommendation: Have a Professional Do This

How to use this list even if a pro does the work

Read through before your service appointment. It tells you every step that should be completed, what supplies the tech is using, and what to ask about when you pick up your trailer.

Supplies — Order 2–3 Weeks Before Your Appointment

Step 1 — Dump & Flush All Tanks First (30–45 min)

Do This Before Everything Else

Never winterize with full or partial tanks. Follow the Water Dump Procedure in full, then add a double dose of black tank enzyme treatment.

Step 2 — Drain the Fresh Water System (20–30 min)

Water Heater Bypass — Saves 2 Gallons

Before adding antifreeze, engage water heater bypass valves to isolate the heater from the plumbing circuit. If not already installed, add the Camco bypass kit ($10–20).

Step 3 — Add Antifreeze to Plumbing (30–45 min)

⚠ Pink RV Antifreeze Only

Never use automotive antifreeze (ethylene glycol) — it is toxic and will contaminate your water lines. RV antifreeze is propylene glycol. It looks pink. Anything else is wrong.

Step 4 — Battery & Electrical (15 min)

  • Turn off all 12V lights, fans, and appliances inside
  • Disconnect shore power cord
  • Charge battery to full before storage if possible
  • Option A (preferred): Remove battery, store indoors above 32°F, connect to NOCO GENIUS2 maintainer
  • Option B: Leave battery in trailer, connect smart maintainer if shore power is accessible at storage
  • If removing: disconnect negative terminal first, then positivestore in ventilated area

Battery Left Uncharged in Winter = Permanent Damage

A 12V lead-acid battery left discharged in freezing temps suffers permanent capacity loss in as little as one winter. A $30 smart maintainer pays for itself in avoided replacements.

Step 5 — Exterior Inspection & Seals (30–45 min)

80% of RV Water Damage Enters Through Failed Seals

Five minutes of lap sealant in the fall prevents thousands in delamination and mold remediation in the spring. Walk the entire roof and every seam.

  • Wash exteriorremove road grime and bugs before storage
  • Apply UV-protective wax or coating
  • Inspect entire roof: cracks, separation, or dried sealant around all vents, skylights, A/C, and antenna base
  • Apply Dicor 501LSW lap sealant to any cracked or separated seamseven hairline cracks
  • Apply rubber roof conditioner across the full roof surface
  • Inspect all window and door frames for sealant gapsrecaulk any separations
  • Inspect slide-out seals: run hand around perimetershould spring back, not crack
  • Apply slide-out rubber seal conditioner
  • Check underside: water line insulation, any exposed plumbing

Step 6 — Tires, Wheels & Security (15 min)

Tires Develop Flat Spots After 30 Days Stationary

Place trailer on leveling blocks or tire cradles for storage longer than 30 days. Move the trailer a few inches every month if possible.

  • Inflate all tires to maximum sidewall pressure for storage (higher than driving pressurereduces flat spots)
  • Place leveling blocks or tire cradles under tires for long-term storageBuy ↗
  • Install UV tire covers on all 4 tires
  • Lower tongue jack and stabilizer jacks slightly to take some load off tires
  • Install coupler lock / hitch lock to prevent theft during storage

Step 7 — Pest & Moisture Prevention (15–20 min)

Mice Will Find Your Trailer

A stored trailer is a perfect winter home for rodents. They enter through gaps as small as a dime and nest in insulation, chew wiring, and destroy soft goods. Skip this step once and you may spend 8 hours cleaning in spring.

  • Place rodent repellent pouches: one per storage bay, one under sink, one near water pump, one near furnace intake
  • Stuff steel wool into any visible gaps around wiring, plumbing, and slide openingsrodents cannot chew through steel wool
  • Close all roof vents
  • Place 2–3 DampRid moisture absorbers inside
  • Remove ALL food itemspantry, fridge, and all bays
  • Leave fridge and freezer doors propped open (rolled towel)prevents mold
  • Remove linens, pillows, and mattress coverslaunder and store at home
  • Close and latch all window blinds and shades

Step 8 — Final Lockdown (10 min)

  • Water heater: drain plug reinstalled (hand-tight), pressure relief valve closed
  • Low-point drain valves: CLOSED
  • All faucets: CLOSED
  • Water pump switch: OFF
  • Propane: tank valve CLOSED
  • Shore power cord: disconnected and stowed
  • Battery: removed or maintainer connected
  • All exterior compartments: closed and latched
  • Entry door: locked
  • Hitch: coupler lock installed
  • Tire covers: on all 4 tires
  • Take a walk-around photo of the traileruseful reference for spring inspection
Field Notes

Things worth knowing

01

Blow out first with compressed air, then run antifreeze through. Air clears the bulk water; antifreeze handles what air can't reach — P-traps, low points, and the water heater bypass lines.

02

Label your winterized status. Put a piece of tape on your water pump switch that says WINTERIZED. The next person to open that trailer in April (possibly you) will thank you.

03

Don't forget the ice maker, outdoor shower, and washer/dryer connection if you have them. These are the winterization misses that show up as expensive spring repair bills.

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