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How to Winterize a Camper | Antifreeze, Air & Water Lines

For many camper owners, the beginning of October marks the end of another season of travel. 

As the nights draw in and autumnal hues give way to bare branches and grey skies, it’s a sure sign winter is on the horizon.

Unless planning to live in the camper in the winter months, now is the time to pack everything up and get it ready for winter storage.

This post provides a step by step guide on how to winterize your camper van.

We’ll cover off what it means to winterize an RV and what you need to get the job done so you can return in spring, ready to hit the road once more. 

How to Winterize a Camper for Pinterest

Winterizing an RV | What Is It & Why Do It?

Winterizing an RV, motorhome or travel trailer prepares it for the harsh winter months ahead.

Leaving an RV in storage during cold, wet wintery conditions could spell trouble unless it’s been prepared properly.

Frozen water lines could crack and burst, causing untold damage to heating components and the plumbing system, potentially flooding the interior. 

Rodents and bugs could move in as you move out so you can add fumigation to your list of jobs to do before spring break.

And the electrical system needs a bit of care too so you don’t shorten the life of those expensive batteries.

Returning to a long list of problems in spring is not the best start to the season.

RV Winterizing Kit

There are a few accessories you need to complete the task of preparing a camper for winter storage. 

You can buy RV winterizing kits but these tend to focus only on the accessories needed to prepare the water system for freezing conditions. 

For each step in the guide below, we’ve listed everything you need. 

You probably already have most of these items though there are a few specific accessories too.

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1. Unpack the Camper

Accessories needed:

While packing an RV is exciting, unpacking is a bit of a drag! 

But it’s a necessary chore and when it comes to spring, it’s a job you’ll be glad you’ve done well.

Unpacking an RV before putting it into winter storage

If you have a dedicated space in your garage or home for gear, so much the better.

  • Take out all valuables including the contents of the safe
  • Take out all food items from cabinets and the fridge/freezer
  • Remove anything that could succumb to the cold air including soft furnishings, curtains, bedding, books and clothes

Ensure any items you leave in the van over winter can’t be damaged if exposed to extreme cold.

2. Deep Clean your RV

Accessories needed:

  • Gloves
  • Cleaning products for floors, windows and general-purpose
  • Vacuum or brushes
  • Sponges, cloths & rags
  • Boxes of baking soda
Unpacking an RV before putting it into winter storage

Deep cleaning not only prevents bugs and rodents from sniffing out rogue crumbs but makes the camper trip ready for next year too.

More often than not, a deep clean helps you find small maintenance jobs you could otherwise easily overlook.

If it’s warm enough, open up all the doors and windows as you go. It helps to get rid of the smell of cleaning products and dries things off quicker too.

Start on the ceiling and work your way down, vacuuming or sweeping as you go.

  • Clean roof vents
  • Wash the windows
  • Wipe down walls and doorways, especially areas where dirt can accumulate
  • Vacuum and clean cabinets – inside and out
  • Switch off, disconnect and clean all fitted kitchen appliances – stovetop, oven, microwave etc
  • Defrost and deep clean the refrigerator and freezer, leaving the door ajar to keep it dry, fresh and mould free
  • Clean the bathroom including the walls, sink, shower tray and vents
  • Vacuum and clean floors

Top tip | Placing boxes of baking soda in the fridge and enclosed spaces like cabinets will help absorb moisture and odours, keeping the camper fresh and dry.

3. Winterize Portable Camping Toilet

Accessories needed:

Winterizing portable camping toilets and cassette toilets is pretty much the same as emptying it but with a deep clean.

  • Empty the portable toilet
  • Thoroughly rinse the holding tank 
  • Add cassette tank cleaner. You’ll need to mix it with water. Follow the guidelines on the bottle for the correct measure
  • Leave it to sit for at least 24 hours
  • Empty the cleaning fluid and allow the cassette to dry thoroughly, leaving all vents open

4. Winterize a Composting Toilet

Accessories needed:

  • Gloves
  • Vinegar
  • Paper Towels
Winterising camping toilets, composting toilets and black tanks is an important part of the process

Winterizing a composting toilet doesn’t take much effort at all.

Simply empty the “pee pot” and give it a deep clean by rinsing it in a light vinegar and water mixture. 

Allow it to dry thoroughly before returning it to the toilet.

For the solids box, you can make a call on whether to leave the material or empty it. 

Leaving the composting material unused for months allows decomposition to continue. 

Once the temperatures plummet, any moisture in the compost will freeze but there’s plenty of space in the holding tank for this not to cause any damage.

Towards the end of the winterizing jobs, you’ll switch off the camper’s electrical system so the composting toilet fan won’t work. 

So long as you’re not replenishing it with fresh deposits, the contents will continue to dry out so when you return in spring, it’ll be fresher.

If you’d prefer, empty the contents and deep clean the box.

Finally, disconnect its electrical supply.

5. How to Winterize the Water System

The water system is the most critical part of winterizing a camper. If not done correctly you could end up with a hefty repair bill come spring.

You could pay for an RV winterizing service but it’s easy to do yourself. It doesn’t take as long as you might think either, about half an hour all told.

There are 2 ways to prepare the hot and cold plumbing system for the winter months:

  • Antifreeze – fills the waters lines so any residual water can’t freeze solid
  • Air – dries the water lines to rid them of any moisture

How To Winterize An RV With Antifreeze

In areas where winters are long and cold, antifreeze is the most popular way to winterize the water system.

Antifreeze does still freeze but it only turns gloopy rather than a solid block of ice, so it doesn’t damage delicate pipes and other plumbing components.

Accessories needed:

RV water pipes can be winterized with compressed air or antifreeze
  1. Drain the black water tank, responsibly 
  2. Clean the holding tank – a clear sewer hose will help you see when it’s running clean
  3. Remove all inline water filters. Note, some inline water filters need a bypass hose when the filter is removed
  4. Turn on the water pump 
  5. Drain and rinse the grey holding tanks, responsibly
  6. Drain the water heater – make sure it’s cold first
    1. If your water tank runs on mains electricity supply, disconnect it when it’s empty so there’s no risk of accidentally switching it on. It would destroy the element
    2. Install the water heater bypass kit and switch it to bypass
    3. If you have a water heater tank, empty it by removing the drain plug
  7. Completely drain the fresh water tank
    1. Open the drain plugs
    2. Turn on all the taps/faucets and showerhead to help force the water out
    3. If you have low point drain lines, open them too
    4. Once empty, close the drains
  8. Switch off the water pump
  9. Double-check all drain holes are closed
  10. If not already fitted, install a water pump converter
  11. Pump the system with non-toxic antifreeze through the winterization valve on the pump
  12. Open each tap in turn until antifreeze appears, starting with the one closest to the water pump. Repeat for all taps, showers and toilets
  13. Close all faucets and taps
  14. Your RV water system is now winterized

Do I Need a Water Heater Bypass?

This method of protecting camper water lines from freezing uses a LOT of antifreeze.

If you also need to fill the water heater, you could easily use 3 or 4 times more antifreeze and this stuff isn’t all that cheap.

A water heater bypass kit does what it says on the label – it bypasses the heater so you don’t need the extra gallons of antifreeze.

How To Winterize An RV With An Air Compressor

You'll need an air compressor for this job

Winterizing a camper with an air compressor is a less expensive method and it doesn’t use so much antifreeze.

  1. The first 8 steps are the same as for the antifreeze method – cleaning and draining all the onboard holding tanks, though you don’t need to fit a water heater bypass kit
  2. Open all faucets or taps
  3. Connect the air compressor to the water inlet valve with the blow out adaptor
  4. Slowly increase the pressure but don’t go over about 10 psi (certainly no more than your pump) for fear of damaging the pipes
  5. The remaining water will splutter out of the taps and toilet
  6. Depending on how your water system is plumbed, you may need to connect a bypass kit so air can reach the hot water pipes from the cold water system too
  7. Once no more water is being blown out, the system is dry
  8. Finish the job by pouring a cup or 2 of antifreeze down the sinks, shower drains

Is blowing out RV water lines vs antifreeze a better option? 

Meh, it’s as much down to personal preference as anything else. Both methods will protect the camper water system.

But when it comes to de-winterizing the camper in spring, all that antifreeze needs to be drained. 

While it’s not toxic, so safe in your water system, it’ll take a hell of a lot of flushing and baking soda to get rid of the residual taste.

6. Disconnect the Camper Electrics

Accessories needed:

  • Electrical tool kit
Winterizing the camper electrical system is important too to save the expensive batteries from freezing

Make sure all electronic appliances and gadgets are disconnected from their sockets.

To protect the entire electrical system, turn off the isolator switches to and from the campervan batteries.

This ensures no power is running to or from them so the system is safe.

Some batteries fair better in colder climates but none are great in freezing temperatures.

If possible, remove the leisure batteries and store them somewhere cool and dry.

You may need to monitor the batteries’ health while they’re not in use so make sure you know what is required for your battery type.

7. Isolate Propane Tanks

Switch off all the propane tanks. If you use the portable bottles, disconnect them and remove them if possible.

For fixed propane tanks, shut off the isolator valve.

8. Close up all external outlets

Accessories needed:

Walk around the camper to check all external vents and exhausts.

They make perfect ideal entrance halls for unwanted winter squatters like bugs and rodents.

You can buy mesh vent covers to prevent this or stuff them with steel wool.

Just remember to unplug them all when de-winterizing in spring.

It’s a good time to double-check all window and roof seals are intact too.

9. Wash the camper

Saying farewell to camper going into storage at the end of the season

Give your camper a well deserved external valet. Clean all mirrors, wheels and inside the wheel arches and treat her to a wax treatment. 

Don’t forget the awning, the roof and solar panels too.

10. Park & Store

Your camper is winterized now and it’s time to park her in a winter storage spot.

If you have metal fuel tanks, fill them up. The fuel helps protect the inside of the tank from rust build-up. In freezing temperatures use cold weather fuel additives.

When storing your RV, it’s best to park her level and using axle blocks to position the wheels off the ground.

This prevents flat spots on the tyres from being parked in the same place for a prolonged period.

If unable to jack her up, using wheel chocks or leveling blocks to at least make sure she’s parked level.

Then disconnect the starter battery so it isn’t flattened by your alarm system, clocks and so on.

Cover the camper with a winter camper cover. Avoid plastic tarps if possible because they don’t allow the air to circulate so well and could lead to problems.

If the camper is parked outside and the wheels are exposed, consider fitting tyre covers to protect them from the frost.

If you want to go the extra mile, you can attach your RV skirting to provide an additional layer of insulation to teh RV underbelly.

If possible, pay a visit to your camper occasionally to check up on her. 

A quick inspection will put your mind at rest that there are no leaks, unpleasant smells from a forgotten rogue tomato or a family of pests moved in.

If you do find any problems, you’ll have fair warning to get them resolved before the spring, which will be here before you know it!

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