Jayco Winterizing Instructions

32°F (0°C) is the point at which you should winterize an RV if it will be exposed to freezing weather. The job is mainly about removing or displacing water in the plumbing so it cannot freeze, expand, and damage lines or the water heater. Jayco provides two workable methods: blowing out the water lines with air or pumping non-toxic RV antifreeze through them.

Winterizing Task	Jayco Procedure
Cold-weather trigger	Winterize when the RV may be exposed to 32°F (0°C) or below.
Air-pressure method	Run the pump dry for about 15–20 seconds, then blow air through the City Water Fill for five to ten minutes.
Drain traps after air method	Pour one cup of non-toxic RV antifreeze into every drain P-trap.
Antifreeze method	Turn off the water-heater controls, bypass the heater, close the fresh-tank and low-point drains, then pump RV antifreeze through each fixture.
Holding tanks for storage	Keep the fresh-water tank as empty as possible; retain about 7 percent water in the black and gray tanks with tank treatment.

When To Winterize a Jayco RV

Winterize at the end of the camping season or before storage when freezing temperatures are possible. A heated campsite or a “four-season” RV does not remove the need to protect plumbing if the trailer or motorhome will sit unattended in freezing conditions.

Winterizing protects two separate systems: pressurized water lines and the water held in fixture traps and holding tanks.

Before you start, identify the parts that matter on your Jayco:

City Water Fill connection
Fresh-water tank drain
Low-point drains
Water-pump access
Water-heater bypass valves
Water-filter housing, if equipped
Indoor and outdoor faucets, shower, toilet, and any exterior spray port

Locations vary by floor plan. Before draining the system, use the owner’s manual for your exact model to identify the City Water Fill, drains, water-pump access, and water-heater bypass valves.

How To Winterize a Jayco RV

Choose one method for the supply lines: air pressure or RV antifreeze. Both methods still require protection for drain traps. Never use automotive antifreeze in an RV plumbing system; use non-toxic RV antifreeze made for RV water systems.

Step 1: Empty and Drain the Water System

Park the RV level and disconnect it from city water.
Empty the black and gray tanks at an approved waste disposal station. Clean and flush the tanks before storage.
Drain the fresh-water tank and fresh-water plumbing system.
According to Jayco, Inc., drain the water heater after it has cooled.
Open the appropriate faucets and low-point drains to let the plumbing drain.

If you are using the air-pressure method, make sure the holding tanks are empty and their drain valves are open before blowing out the lines.

Air-Pressure Method

Use this method when you have an air hose and a compatible blowout adapter for the City Water Fill connection.

With the fresh-water system drained, run the water pump until it runs dry, which takes approximately 15–20 seconds.
Follow the manufacturer’s or the official safety guidance for this step.
Blow air through the plumbing for five to ten minutes. Open all faucets, drains, and the toilet before blowing air through the plumbing so water can escape from the system. Include the shower, outdoor shower if equipped, and toilet water valve.
Pour one cup of non-toxic RV antifreeze into every sink, shower, and tub drain so each P-trap contains antifreeze.
Close the black- and gray-tank drain valves for storage. Keep the fresh-water tank as empty as possible, then retain about 7 percent water in the black and gray tanks and add tank treatment.

Antifreeze Method

Use this method to fill the RV’s water lines with non-toxic RV antifreeze after draining the fresh-water plumbing and setting the water-heater bypass valves. It is a practical choice when you want visible confirmation that each fixture line has been protected.

Level the RV and drain the fresh-water plumbing system.
If your Jayco has an inline water filter, remove the filter cartridge and install the clear plastic bypass hose.
Make sure both the water heater’s 12-volt and 120-volt interior control switches are OFF.
On a Jayco towable, turn the water-heater bypass valves to the BYPASS position. On a Jayco motorized RV, move the valves to the “Sanitize/Winterize Lines” position.
Close the fresh-tank drain and low-point drains. On Jayco motorized models, the low-point drains must be closed or the antifreeze will not siphon through the plumbing lines.
Place one end of a garden hose into a container of non-toxic RV antifreeze and attach the other end to the City Water Fill connection. Keep the hose end submerged in antifreeze throughout the process.
Turn on the water pump.
Open the hot side of one faucet at a time. When pink RV antifreeze flows from that fixture, close the hot side. Repeat at every faucet and shower.
Repeat the process with the cold side of every faucet and shower.
Run RV antifreeze through the toilet until it enters the bowl and plumbing line.
Turn off the pump, remove the hose from the antifreeze container, and wipe antifreeze from sinks, shower surfaces, and the toilet with a soft, dry cloth to prevent staining.
Set up the holding tanks for storage: leave the fresh-water tank as empty as possible, and keep about 7 percent water in the black and gray tanks with tank treatment. Jayco recommends this storage condition to help prevent bacteria growth or solidification in the holding tanks.

Model-Specific Jayco Winterizing Details

Jayco Travel Trailers and Fifth Wheels

Look for the bypass valves near the water heater, often behind an interior access panel. Do not guess at valve orientation based on another trailer’s video or diagram; Jayco plumbing layouts differ by model year and floor plan.

Jayco Motorized RVs

Jayco motorized products use the “Sanitize/Winterize Lines” valve position during the antifreeze process.

Motorhomes may have more water outlets than a travel trailer, such as an exterior shower. Treat every faucet and water outlet as part of the system, not just the kitchen sink and bathroom sink.

Jayco RVs With Water Filters

Install the clear plastic bypass hose if your RV is equipped with one.

In spring, reinstall a suitable filter cartridge after flushing the plumbing and returning the water heater to normal operation.

Confirm the Plumbing Is Protected

For the air-pressure method, verify that:

Water no longer runs from any faucet when it is opened.
The water pump is off.

For the antifreeze method, verify that:

RV antifreeze flowed through the hot and cold water lines at every faucet.
The toilet line received antifreeze.

Finish the storage routine by cleaning out food, wiping down interior surfaces, checking for obvious gaps that could allow pests inside, and closing all exterior plumbing compartments. Avoid reconnecting water or flushing fixtures after winterizing, since doing so can introduce water back into protected lines.

De-Winterize Your Jayco in Spring

De-winterizing reverses the process and gives you a chance to find leaks before a trip.

Inspect exterior hoses, fresh-water connections, and visible plumbing for cracks or leaks.
Check the interior for signs of rodents, nests, or damaged wiring and plumbing.
Make sure holding-tank drains are closed, then connect a safe water supply.
Run water through the lines to flush out the antifreeze. Dispose of the flushed antifreeze through an approved RV waste disposal station.
Replace the water-heater drain plug and move the bypass valves back to the normal operating position so the heater can refill.
Keep a hot-water faucet open while the water heater fills to let air escape.
Reinstall the water-filter cartridge if you removed it for winter.
Inspect visible water lines for leaks.

Do not turn the water heater back on until its tank has refilled with water.

Frequently Asked Questions

When should I winterize my Jayco RV?

Winterize when your Jayco may be exposed to 32°F (0°C) or below, including during storage or a sudden cold snap. Waiting until after a freeze risks damage because trapped water can expand inside plumbing lines, fittings, and the water heater.

Can I winterize a Jayco travel trailer with air only?

You can use air pressure to winterize a Jayco travel trailer’s supply lines, but air does not protect every part of the plumbing. Pour one cup of non-toxic RV antifreeze into each drain P-trap. Jayco’s air-pressure procedure uses an air hose and adapter connected to the City Water Fill, with air blown through the lines for five to ten minutes. You still need to pour one cup of non-toxic RV antifreeze into each drain P-trap because compressed air does not protect standing water in those traps.

How do I winterize a Jayco motorhome?

Use the antifreeze method with the motorized RV’s valves in the “Sanitize/Winterize Lines” position. Close the low-point drains before turning on the pump so the antifreeze can siphon through the plumbing, then run antifreeze through every hot and cold faucet and the toilet.

How do I drain the water system on a Jayco travel trailer?

Park the trailer level, empty the holding tanks, drain the fresh-water tank, drain the fresh-water plumbing, and drain the water heater after it has cooled. Open faucets and low-point drains to release trapped water, then either blow out the lines or fill them with non-toxic RV antifreeze.

Does the water heater need to be bypassed?

Yes when using the antifreeze method. Turn off the water heater’s 12-volt and 120-volt controls before moving the bypass valves, and keep the heater bypassed until you de-winterize and refill it in spring.

Why should you check your Jayco owner’s manual before winterizing a specific model?

You should consult the documentation for your own Jayco before starting because RV systems and the sequence of winterizing tasks can vary. Jayco directs owners to their manual for instructions that apply to their particular unit.