RV Winterizing: Find Every Water Line
Build a fixture-by-fixture RV winterizing checklist, identify your water heater’s procedure, and catch overlooked pumps, sprayers, appliances and drains.
The RV Dummies editorial team · Published
Before you open a drain or buy antifreeze, walk through your RV and make a list of everything that holds water. The kitchen faucet is easy to remember. The toilet sprayer behind the bowl, the filter under a cabinet and the outside shower you used once in July are easier to miss. A good winterizing plan accounts for all of them.
The goal is to pair your rig’s approved procedure with a complete fixture list. This guide helps you build that list and catch gaps before cold-weather storage. It does not supply one set of valve positions for every RV. Water-heater designs, plumbing panels and optional appliances differ enough that a shortcut from another rig can send you the wrong way.
Set the date before the first freeze
Choose a winterizing day while you still have time to get an answer or book service. Waiting until the evening before a hard freeze leaves little room for a stuck access panel, an unfamiliar valve or a washer manual you cannot find. Look at the weather where the RV will actually sit, including any overnight stops before it reaches storage.
For example, suppose your last campground weekend ends Sunday and the trailer goes into an unheated storage lot Monday. Plan the water-system work around the trip home, rather than treating the campground checkout as the finish line. Jayco’s 2026 towable manual calls for winterizing at the season’s end or when exposure at or below freezing is expected. A heated living area is not proof that every exterior water component is protected.
If you intend to keep using water in freezing conditions, that is a separate operating plan requiring a rig designed and equipped for it. An appliance’s frost-protection feature does not winterize the rest of the RV.
Sources: Jayco: 2026 Jayco Family Towable Owner’s Manual, plumbing pp. 71–75 · Truma, hosted by Forest River: Truma AquaGo Basic, Comfort and Comfort Plus Operating Instructions
Build a one-page job sheet
Start with the model year and floor plan of the RV, then record the water heater, water pump, toilet and any water-using appliances by exact model. Download the matching owner and component manuals before you begin. Keep the winterizing pages together so you are not switching between a forum answer, an old video and a different model’s diagram halfway through the job.
Give each fixture a row with four fields: location, manual page, required treatment and completion check. Write specific locations such as “outside shower in rear driver-side compartment,” rather than simply “outside.” Leave room for a note about a removed filter or a drain that must stay in a particular position.
Take clear photos of the existing labels and normal valve positions for reference. Then compare the manual diagram with the plumbing you can see. If a previous owner changed the system, or the drawing does not match, resolve that before moving valves. A question mark on the sheet is unfinished work, not a box to check later from memory.
Sources: Jayco: 2026 Jayco Family Towable Owner’s Manual, plumbing pp. 71–75 · Winnebago: Operator Manuals
Cool and shut down before you drain
Treat the water heater as a separate job. Turn off its heat sources using the controls specified for the appliance, allow the water and unit to cool, switch off the onboard water pump, and shut off or disconnect city water. Relieve pressure by the manufacturer’s procedure before opening a drain or removing a plug. Never loosen a hot or pressurized heater’s drain plug to see whether water remains.
Put a clear reminder at the heater controls that the water system is being winterized. This is especially useful when two people are working or someone returns later to plug the RV into shore power. The person bringing the rig back into service needs to know that filling, valve restoration and leak checks come before normal heater operation.
If you cannot positively identify the shutdown, depressurizing and draining steps, stop there and get help. Guessing at a relief valve or drain is not a worthwhile way to save a service visit.
Sources: Truma: Time to Winterize: Truma AquaGo · Jayco: 2026 Jayco Family Towable Owner’s Manual, plumbing pp. 71–75
“Tankless” does not mean one procedure
Find the appliance name before deciding whether to bypass it. The on-demand layout illustrated in Jayco’s 2026 towable manual allows antifreeze through the heater with the heater off. Its storage-tank layout uses a bypass. Those drawings describe those installations; they are not a rule for every water heater sold as tankless.
Truma AquaGo is an important counterexample. Its winterizing instructions call for shutdown, complete cooldown, pressure relief and the installation’s bypass arrangement, followed by the Easy Drain Lever and filter-cartridge process. The unit has water in a mixing vessel that must drain. Truma discourages high-pressure air and antifreeze inside the appliance and specifies an installed bypass when antifreeze is used in the RV plumbing.
Write the heater’s actual process on its own row, including what confirms drainage and where removed parts will be stored. If the RV manual and installed appliance instructions appear to conflict, ask the manufacturer or a qualified RV technician to reconcile them before proceeding. The word “tankless” is not enough information to choose.
Sources: Jayco: 2026 Jayco Family Towable Owner’s Manual, plumbing pp. 71–75 · Truma: Time to Winterize: Truma AquaGo
Walk every indoor fixture
Work through the living space in a consistent direction and list both hot and cold paths wherever they exist. A single-handle faucet still serves two supply paths. Include the kitchen, bathroom sink and shower, then look for a pull-out kitchen sprayer, shower hose and hand-held head. Use the matching procedure for each accessory rather than assuming the nearest faucet covers it.
The toilet deserves its own row. Dometic’s 300, 310 and 320 instructions address the toilet water valve and, when fitted, the hand sprayer. Putting antifreeze into the bowl alone does not establish that the supply components have been treated. Follow the toilet’s instructions together with the RV’s approved antifreeze delivery or draining method.
For example, if your helper says “the bathroom is done,” ask which rows are complete: sink hot, sink cold, shower, toilet and sprayer. That small change in wording prevents one finished tap from standing in for an entire room.
Sources: Winnebago: 2025 Winnebago Towables Owner’s Manual, plumbing and winterization pp. 60–63 · Dometic: Dometic 300, 310 and 320 Series Toilets Operating Manual
Give the pump and filters their own check
Locate the pump and its inlet strainer before starting. A strainer is the small screen or bowl that catches debris before it enters the pump; it is not necessarily your drinking-water filter. Add the pump, strainer and every separate filter housing to the sheet. Record whether the installed instructions call for draining, cartridge removal, a bypass or another specific treatment.
The 2025 Winnebago Travato manual explicitly tells owners using its blowout procedure to empty the pump-strainer bowl. Water left there can freeze and crack it. Pentair’s Shurflo 4008 manual also gives the pump its own winterizing procedure. Air coming from a kitchen faucet does not demonstrate that these components are protected.
Do not turn the pump’s pressure or internal bypass adjustments while trying to find a winterizing setting. Those adjustments are different from the RV’s plumbing-selector valves. Pentair reserves the 4008’s internal bypass adjustment for a properly equipped professional.
Sources: Winnebago: 2025 Travato Operator’s Manual, plumbing pp. 7-2 and 7-19 · Pentair: Shurflo 4008 RV Revolution By-Pass Pump Installation and Operation Manual
Check outside and behind appliance doors
Do an exterior pass while your list is still in hand. Look for an outside shower, spray port, outdoor kitchen sink, city-water connection, tank-fill arrangement and black-tank flush connection. A flush connection is a separate waste-system item; do not use its hose as your drinking-water hose. Follow its specific winterizing directions instead of assuming work through the fresh-water inlet reaches it.
Then open the doors that hide optional equipment. A washer, ice maker, refrigerator water dispenser, dishwasher or water-treatment system needs a model-specific answer. If an item is installed but you rarely use it, do not assume its water connections are empty.
The Splendide WFL1300XD manual, for example, provides an RV winterization sequence that operates inlet valves and the drain cycle, plus a separate alternative addressing hoses. Running a nearby sink cannot substitute for that process. Add the appliance’s complete procedure to your job sheet; do not borrow its cycle timing for a different washer.
If access is too tight to identify a connection safely, put that item on a technician’s work order rather than declaring the whole RV finished.
Sources: Winnebago: 2025 Winnebago Towables Owner’s Manual, plumbing and winterization pp. 60–63 · Splendide: Splendide WFL1300XD Instructions for Use, RV/Marine Winterization · Jayco: 2026 Jayco Family Towable Owner’s Manual, plumbing pp. 71–75
Separate supply lines from drain traps
Water arriving at a faucet and water leaving through a drain follow different paths. Low-point drains help empty the supply plumbing according to the RV’s procedure. The curved P-trap under a sink or shower is designed to retain water on the drain side. Opening supply drains does not automatically complete the trap’s winterizing step.
Make a separate drain-side pass: kitchen sink, bathroom sink, shower or tub, and any other installed drain or waste-handling equipment. Use the amount and treatment specified for your system. An RV with a different drain design or macerator needs its own instructions, not an extra splash added by guesswork.
Also list the fresh-water tank and its drain, hot- and cold-line low-point drains, and the gray- and black-water tanks, termination valves and any macerator. Each needs the storage preparation specified for the installed system.
This is a useful point to reconcile the sheet with the actual rig. Count the drains you can identify and compare that count with the completed rows. If a drain is missing from the list, add it before you put away the supplies.
Sources: Winnebago: 2025 Winnebago Towables Owner’s Manual, plumbing and winterization pp. 60–63 · Camco: How to Winterize Your RV, antifreeze FAQ
Read the antifreeze label, not just the color
Use only a winterizing product explicitly labeled for RV potable-water systems and compatible with the equipment it will contact. Automotive coolant and windshield-washer fluid do not belong in the drinking-water plumbing. Pink color alone is not a specification, and “nontoxic” on a winterizing product does not make it drinking water.
Check whether the product is ready to use or requires a particular preparation, and follow its label. Do not improvise a dilution to stretch the last jug. Water left in the system can dilute the product as well, which is one reason the approved draining and displacement steps matter.
Also distinguish burst protection from freeze point. Camco explains that an RV antifreeze can form ice crystals at a temperature warmer than its stated burst-protection rating. The large number on the container does not promise the liquid will stay freely flowing down to that temperature. Record the exact product used so there is no guessing when service or spring flushing comes around.
Sources: Camco: How to Winterize Your RV, antifreeze FAQ · Dometic: Dometic 300, 310 and 320 Series Toilets Operating Manual
Do not borrow somebody else’s air setting
If your approved procedure uses compressed air, use the specified regulator, connection, pressure and sequence. Manuals differ: the 2025 Winnebago towables guide describes approximately 20 psi for its city-water and black-tank inlet blowout steps, while the 2025 Travato procedure limits regulated pressure to 30 psi and calls for slow admission without bursts. These are examples of why a setting from another rig is not a universal answer.
Confirm that the method also covers the installed heater, pump and accessories, and complete any separate trap treatment. A compressor and a dry-sounding faucet do not replace the rest of the checklist. If you cannot control pressure reliably or the appliance instructions do not permit the method, stop and choose an approved alternative with the manufacturer or technician.
Sources: Winnebago: 2025 Winnebago Towables Owner’s Manual, plumbing and winterization pp. 60–63 · Winnebago: 2025 Travato Operator’s Manual, plumbing pp. 7-2 and 7-19 · Truma: Time to Winterize: Truma AquaGo
Finish with a second walk-through
After completing the actual manufacturer procedures, put the tools down and walk the list again. Check each row against what you observed, not what you intended to do. Confirm the required final positions of valves, drains and controls, and make sure the pump and heater are left in the specified storage state.
Label any intentionally disconnected plumbing and keep removed cartridges, plugs or other parts clean and identified according to their instructions. Record the date, method, product and unresolved issues. A photograph of the final labeled valve panel can help the next person understand the storage configuration, but it is not a substitute for the manual.
If a component did not drain as expected, treat that as a problem to resolve. Truma’s Combi instructions, for instance, require checking that its water container actually empties and identify drain obstruction as a possible issue. A completed-looking checklist is only useful when the steps really happened.
Sources: Pentair: Shurflo 4008 RV Revolution By-Pass Pump Installation and Operation Manual · Truma: Time to Winterize: Truma Combi
One more trip means another water-system check
Suppose a mild weekend tempts you to take the winterized RV out again. Before reconnecting water, work through the proper return-to-service procedure, including required flushing, sanitizing, valve restoration and leak checks. Keep the heater off until its filling and startup requirements are satisfied. Winterizing and sanitizing solve different problems.
When that trip ends, do not rely on the earlier winterizing date. Any branch you put back into use needs to be accounted for again before freezing exposure. Update the job sheet so it tells the current story of the RV, rather than preserving a reassuring date from last month.
The best result is a repeatable routine you can explain: every water-holding component identified, its correct procedure followed, and the final condition recorded. If one item remains uncertain, that is the question to bring to the service shop.
Sources: Truma: Get Ready for Spring with Truma · Pentair: Shurflo 4008 RV Revolution By-Pass Pump Installation and Operation Manual
Sources & date notes
- 2026 Jayco Family Towable Owner’s Manual, plumbing pp. 71–75 · Jayco
2026 model-year manual, document 26.2047700; downloaded PDF records a July 21, 2025 modification. Applies only to the described installations. Checked 2026-10-18T19:24:20Z.
- Operator Manuals · Winnebago
Manufacturer’s model-year manual directory checked October 18, 2026. Use the exact model and installed component documentation. Checked 2026-10-18T19:22:20Z.
- 2025 Winnebago Towables Owner’s Manual, plumbing and winterization pp. 60–63 · Winnebago
Cover and copyright identify 2025 model year. Fixture list and air-pressure examples are specific to this manual. Checked 2026-10-18T19:24:26Z.
- 2025 Travato Operator’s Manual, plumbing pp. 7-2 and 7-19 · Winnebago
2025 manual, revision 2507250813. Model-specific pump-strainer and regulated-air guidance; not a universal pressure specification. Checked 2026-10-18T19:24:26Z.
- Shurflo 4008 RV Revolution By-Pass Pump Installation and Operation Manual · Pentair
Manufacturer-hosted document 911-1008, Rev. K, December 2014. Guidance is specific to the Shurflo 4008. Checked 2026-10-18T19:23:42Z.
- Time to Winterize: Truma AquaGo · Truma
Published October 19, 2022; current manufacturer page read October 18, 2026. Applies to AquaGo, not all tankless heaters. Checked 2026-10-18T19:22:02Z.
- Truma AquaGo Basic, Comfort and Comfort Plus Operating Instructions · Truma, hosted by Forest River
Manufacturer operating instructions hosted in Forest River’s component library; frost-operation cautions distinguish appliance protection from the entire RV. Publication date not established. Checked 2026-10-18T19:28:01Z.
- Time to Winterize: Truma Combi · Truma
Published October 17, 2022; manufacturer drainage and bypass guidance checked October 18, 2026. Checked 2026-10-18T19:28:01Z.
- Dometic 300, 310 and 320 Series Toilets Operating Manual · Dometic
Rev. D, October 2020, printed pp. 12–13. Toilet and sprayer guidance is model-specific; antifreeze delivery must also match the RV’s plumbing instructions. Checked 2026-10-18T19:28:01Z.
- Splendide WFL1300XD Instructions for Use, RV/Marine Winterization · Splendide
Manufacturer-hosted manual, p. 15; publication date not visible in retrieved text. Applies only to WFL1300XD. Checked 2026-10-18T19:24:20Z.
- How to Winterize Your RV, antifreeze FAQ · Camco
Manufacturer-hosted eight-page guide; issue date not established. Used for drain-side distinction and freeze-point versus burst-protection explanation. Follow the current label of the actual product. Checked 2026-10-18T19:22:20Z.
- Get Ready for Spring with Truma · Truma
Manufacturer return-to-service page checked October 18, 2026. Appliance-specific filling and air-purging guidance; no universal sanitizing recipe supplied. Checked 2026-10-18T19:28:01Z.
Editorial notes & corrections
Original practical synthesis reviewed against the linked manufacturer sources. The diagrams were drawn for this article and show concepts and an illustrative fixture layout, not a real RV, exact plumbing route or valve settings. Example situations are illustrative; no firsthand testing or family experience is claimed. Procedures must match the actual RV and installed components.
No corrections have been recorded.