• Winterizing your motorhome helps prevent costly damage from freezing temperatures and moisture.
• Focus on draining water systems, protecting your engine and batteries, sealing gaps, and caring for the interior.
• Even small missed steps, like forgetting to blow out water lines, can lead to expensive repairs in spring.
• Tackling these tasks yourself saves money, but you may prefer professional help for the trickier parts.

Winterizing a motorhome means preparing it for low temperatures, snow, ice, and moisture. It keeps your plumbing and mechanical systems safe, extends your RV’s life, and saves you money in the long run. You need to drain water, guard against freezing, and make sure no pests or critters decide to move in. Missing just one part of the process, even as simple as not cracking a vent, can create big problems come spring.

Why Winterizing Matters for Your Motorhome

I see a lot of new RV owners put this off. If you leave your rig parked outside or in an unheated space, any water left in tanks or lines freezes and expands. That splits pipes, bursts faucets, and cracks toilets. Engine coolant can get sludgy. Batteries can die or leak. Upholstery starts growing mildew before you even notice. The truth? Skipping the small jobs here can lead to huge spring invoices. And I’ve seen some folks faced with big plumbing bills they could have avoided with an hour’s effort.

Winterizing isn’t about being fussy. It is about preventing damage. RV repairs in spring almost always cost more than taking these steps now.

How Long Does It Take?

With a good checklist, most people can winterize in two to three hours. Some people get it done faster, but nobody should rush the process. In my case, it sometimes takes longer because I check and double-check pipes. No part of me enjoys replacing a valve I missed because I got lazy last year. It really pays to move carefully.

When Should You Winterize?

The right time depends on where you live. In cold regions, I recommend winterizing before the first steady frost, sometimes late October, sometimes earlier. If you’re in a mild area, you might wait until late November. It is better to be early than sorry. Sudden cold snaps have surprised even the most careful owners.

Motorhome Winterization Checklist

The main job: protect your plumbing, engine, batteries, and interior. Here’s how to tackle each part.

1. Drain and Protect the Plumbing

• Shut off the water pump and disconnect from any water supply.
• Open all faucets, both hot and cold. Flush all toilets. Run the outside shower, if you have one (I nearly forgot this my first year).
• Drain the fresh water tank, the water heater (make sure it is not hot or under pressure), and any low-point drains.
• Open the hot water drain plug. Some tanks have a bypass valve; set this to bypass to avoid filling the whole tank with antifreeze.
• You might need to blow air through all lines. Use a non-oil, low-pressure air compressor. Some people pour RV antifreeze directly into lines instead. Honestly, I think air-blowing is less messy.
• Pump non-toxic, pink RV antifreeze through all lines. Open each faucet, both hot and cold, until you see pink come out. Don’t forget the toilet, outside shower, and city water inlet.
• Poor a cup of antifreeze down each drain and into each P-trap.
• Check and fill the holding tanks with a little antifreeze too.

Plumbing is the heart of RV winterizing. If there is any water left, pipes or tanks can split, even in a single cold night.

2. Protect Your Engine and Fuel System

• Fill your gas or diesel tank. This prevents condensation (which can cause corrosion in the off-season).
• Add a stabilizer to fuel. Run the engine and generator for at least ten minutes to circulate the stabilizer.
• Check coolant levels and antifreeze strength. Most auto shops can test the mix for you; you want this done right.
• If you have a diesel, use anti-gel additives.
• Change your oil and filter. Old oil contains acids and moisture that do more harm if left to sit all winter.
• Lubricate hinges, locks, and moveable parts (bike racks, slide-outs, steps).

3. Care for Your Batteries

• Disconnect all batteries, both engine (chassis) and house batteries.
• Charge them fully before storing.
• If possible, keep batteries indoors somewhere cool but not freezing. Basement or garage shelves work fine.
• If they need to stay in the RV, use a trickle charger or battery maintainer with a timer.
• Clean terminals and apply a thin layer of dielectric grease to prevent corrosion.

Letting batteries sit and drain over winter can destroy them, especially if you let them freeze. A little attention saves a lot of money.

4. Inspect and Seal Exterior Openings

• Look for cracks or gaps around windows, doors, vents, and seams.
• Seal any gaps with appropriate RV caulk.
• Clear leaves, branches, and debris from the roof and gutters.
• Check roof caulking for wear. Sunlight bakes seals all summer, they often need touch-ups by winter.
• Lubricate hinges and locks to guard against ice.
• Cover roof vents. Use vent covers that allow a little airflow but block snow and rain.
• If possible, use a breathable RV cover, not a tarp. Tarps trap moisture and can grow mildew.

5. Clear and Protect the Interior

• Remove any perishables, canned food, grains, and dry goods attract rodents.
• Prop open fridge and freezer doors to prevent mold. I stick a box of baking soda inside each for smell control.
• Vacuum and sweep floors. Wash bedding, remove anything that could collect moisture (books, some clothing, electronics).
• Leave drawers and cabinet doors slightly open for airflow.
• Set out moisture absorbers or dehumidifier packs. If your RV is parked somewhere humid, these are essential.
• Install a few mouse traps or repellents (peppermint sachets are popular, though your results might vary, sometimes they work, sometimes they don’t, in my experience).
• Close blinds and shades to protect fabrics from sun damage.

Moisture and pests love a closed-up RV. Small steps, prop open fridge, use dehumidifiers, check traps, make a difference all season.

6. Prepare Appliances and Propane Systems

• Turn off and disconnect all propane tanks. Store them securely outdoors (never inside the RV or garage).
• Cover regulator with a weatherproof cap or bag. Moisture can ruin them.
• Clean the stove, oven, and any grills. Food crumbs attract animals.
• Check that vents and fans are closed or covered, but you want a little airflow to prevent mold.
• Unplug appliances like coffee makers and toasters. Power surges are rare, but unplugging also prevents phantom draw from electronics.

Frequently Missed Details

• Do you have an outside shower or low-point drains you forgot?
• Are the tires blocked and slightly off the ground? Cold plus sitting ruins tire shape.
• Is the awning clean and dry? Mold forms quickly if left rolled up wet.
• Did you remove your house batteries? Are they charged?
• Is the water heater set to bypass (if using antifreeze)? Otherwise, you will need to flush a big mess in spring.
• Did you add fuel stabilizer and circulate it through your generator?
• Did you check the roof for any tiny cuts or holes?

Everyone forgets one thing their first year. I used to skip the outside shower, until it burst during a December freeze.

How Weather and Storage Impact Your Approach

Winterizing outside is very different from indoor heated storage. If your RV sits inside, you may not need to take every step. But most people, including me, park outdoors or under a simple carport. That means you need full protection.

• If heavy snow is common, clear it off the roof every few weeks. Extra weight will crack seams.
• In rainy climates, moisture is a bigger enemy than cold. Check roof for leaks and use moisture absorbers.
• If temperature swings are frequent, recheck seals a few times mid-winter. Seals shrink and expand, and new gaps can appear.

Recommended Tools and Supplies

Can You Skip Professional Help?

Most motorhome winterizing is pretty simple with the right supplies. Experienced owners usually do it themselves, but everyone starts somewhere. There is nothing wrong with asking for help if this is your first year or if your rig is brand new and you want peace of mind.

Dealers or mobile RV techs can winterize in an hour or two, often for a fee between $150 and $300. You might save some money doing it yourself, but it only works if you do not skip steps. If you use your motorhome year-round and just take quick breaks, you might need to repeat some or all of these steps after each trip. I have met a few snowbirds who skip winterizing entirely, but they usually head south before the first frost, so their approach is different.

Most RV owners can winterize on their own. But getting it wrong can cost more than paying a pro, so consider your experience and comfort first.

Practical Mistakes to Avoid

• Using regular (blue or green) antifreeze. Always use non-toxic, pink RV antifreeze meant for potable water systems.
• Forgetting to bypass the water heater. You’ll waste more antifreeze and create a monster mess.
• Not checking the roof. Small holes grow fast in winter.
• Skipping tank treatment. A bit of antifreeze in all holding tanks saves hassle later.
• Leaving batteries in the RV, disconnected but uncharged. They should be fully charged and checked at least monthly.
• Not covering roof vents. Snow or rain can blow in and cause water damage.

I know one couple who left dry pet food in a cupboard “just for emergency trips”, the result was a family of mice who moved in for the whole winter.

A Simple Winterization Plan

1. Drain all water and waste tanks.
2. Bypass water heater and drain it.
3. Blow out lines or fill with antifreeze.
4. Pour antifreeze into all drains and P-traps.
5. Fill and treat fuel tank and generator.
6. Disconnect and properly store batteries.
7. Seal all external gaps; check roof and seams.
8. Remove food, prop fridge open, clean interior spaces.
9. Protect with cover (breathable) and moisture packs.
10. Inspect every few weeks, especially after storms or snowfalls.

A written plan makes winterizing fast and less stressful. Even a simple checklist on your phone helps avoid those annoying “I forgot…” moments in spring.

Frequently Asked Questions

What happens if you miss winterizing just one trip?

It depends on your area. In warm winters, you might be lucky, but even short freezes can burst pipes or damage fittings. Repairs are much more expensive than prevention.

Can I just use compressed air and not antifreeze?

Some RV owners do, especially in dry, mild regions. But compressed air alone risks missing small pockets of water. I prefer a mix, blow out, then run some antifreeze for safety.

Do I need to winterize if I use my RV now and then during winter?

If you leave it unused for more than a day or two, yes. Winterizing is a must unless you keep it heated constantly (which costs money and has its own problems). If you just take quick weekend trips and temperatures stay above freezing, you might get away with draining lines between trips. But most people find a full winterization less stressful.

Should you run the generator in winter?

Yes, run the generator about once per month for an hour with a load. This helps keep it fresh and lubricated. Fuel stabilizers are a must, or varnish forms inside the components.

How do you keep mice out?

I wish there was a single answer. Some people swear by peppermint oil, others by fabric sheets. I use traps and steel wool in vents and openings. It helps, but mice are determined. The cleaner and emptier you keep it, the better.

Winterizing: Worth your Weekend

Taking the time to winterize stops almost all cold-weather damage in its tracks. Draining, sealing, and storing are a minor investment compared to repairing what freezes, leaks, or molds. You don’t need to be perfect, but you do need to be thorough. Every step matters. Even if it feels like overkill, I think your springtime self will thank you.