03 · Winterization
Cold weather.
Long storage.
To prevent damaging your camper, please refer to all the winterization guidelines provided in your OPUS owner's manual, and the corresponding appliances installed inside your camper.
2025 models
If you own a 2025 OP15, OP13 or Limited Edition, please see the winterization section of your owner's manual.
Winterizing your batteries
Options for your batteries.
Follow these steps for proper battery care and to protect your batteries from depleting over long periods of storage.
We recommend periodically checking your camper or batteries during storage to ensure your chosen storage option continues to work appropriately. Batteries that are not stored appropriately and are allowed to fully discharge may need additional charging outside of your OPUS as the battery charger will not work below a certain voltage. Batteries that are left to discharge below 12 volts may get damaged and not hold charge properly going forward. This damage is not covered under your OPUS warranty.
Plug it in.
Our recommendation is to leave the camper plugged in. You have the ability to leave your OPUS plugged in without the need to remove the 30ah cable. It was designed for easy battery maintenance to protect your batteries from depleting over long periods of storage.
You can maintain your battery using the charge wizard charge controller installed. We have done this because the CO/LP Alarm is hard wired to your batteries and therefore your batteries will supply a constant current to this appliance.
Remove your batteries.
If you choose not to leave your trailer plugged in, you will need to disconnect and remove your batteries entirely from your system. Please follow the below instructions to do so.
- 1Completely charge the battery before storage.
- 2Store the battery in a cool, dry location. Heat is a battery killer.
- 3Completely remove all loads from the battery posts.
- 4Monitor the specific gravity or voltage.
- 5Once below 70% charge, give it a boost charge.
- 6Completely recharge the battery before putting back in service.
- 7Equalize the battery before putting back in service.
Solar panel charging.
It is possible for your solar panels to maintain your battery. The OP15 has 3 x 100w solar panels mounted to the roof and must receive adequate sunlight throughout the winter, thus, this is only a recommended option if your trailer can be stored under the following conditions:
- 1It is not stored under a cover.
- 2The solar panels are clean and free from debris, snow, dirt and dust cover.
- 3There is adequate sunlight reaching the panels.
- 4The panels are properly working.
- 5It is not stored in your garage.
Winterizing your potable water system
Drain it.
Sanitize it.
Please ensure you sanitize, flush and drain the water tanks before first use and after any period of storage. To maintain the cleanliness of your potable water tanks please ensure all water is flushed from your potable water tanks after each trip or every two weeks when in use. Do NOT store water in the tanks for more than two weeks.
To drain your potable water system
- 1Turn off the water pump.
- 2On bottom of both potable water tanks is a drain plug. Open this plug to allow remaining water to gravity drain. Ensure water is collected and disposed of in a responsible way.
- 3Ensure the drain plug is closed again before re-fill the tanks.
- 4Open your faucets, shower and flush your toilet.
To sanitize your potable water system
- 1Flush all water from system as detailed above.
- 2Use a potable water sanitizing product such as Camco TastePURE Spring Fresh Water System Cleaner.
- 3Do NOT use bleach to sanitize the tanks as they are stainless steel and it will cause corrosion.
- 4Follow the steps as directed on your potable water sanitizing product to fill, sanitize and purge as required.
We strongly recommend sanitizing your potable water tanks at least once every six months. If you suspect an issue with the quality of the water in your tanks or notice discoloration, odor or foul taste you should sanitize immediately. Always check your potable water source and use a fill hose listed for use with potable water.
OP15 water system
Truma Combi and the
water heater bypass.
IMPORTANT! Before winterizing your OP15 you must have a water heater by-pass kit installed. Running RV winterizing fluid through your Truma Combi water heater can cause corrosion and Truma advise against this in their manual therefore you must use the by-pass kit to winterize your camper.
If your OP15 was manufactured prior to 2022 and does not have a water heater by-pass kit installed, please contact OPUS HQ for information on ordering a kit and discuss with your local RV service department.
Please be advised that your Truma Combi system has a holding tank in it. Please ensure you carefully read the Truma Combi system manual for steps to drain the water heater tank of this appliance and prepare it properly for winterization. Always wait for the water heater tank to cool before draining.
Empty your tanks and system
Drain the water from your potable water system following the steps listed in the section above. (Figure B2) DO NOT use the water pumps to run your tanks dry.
Set water heater to by-pass mode
- 1Open the drain valve by moving the lever 90 degrees (Figure B) and drain water from Truma Combi (2.64 Gal / 10 L for the complete drain). Note: make sure to keep a bucket underneath the drain valve.
- 2Turn the drain valve back to the closed position.
- 3Turn the 3-way valve (Figure C) handle in a vertical direction (bypass position, Figure A).
At your water pump
- 1Remove the water filter.
- 2Remove the factory-installed cap from the 3-way valve.
- 3Turn the 3-way valve handle in a vertical direction (bypass position).
- 4Attach the clear vinyl hose to the 3-way valve and hand tighten.
- 5Insert the end of the hose into the winterization fluid bottle.
- 6Using the water pump, run this winterizing fluid through the entire water system including the faucets and shower as well. This will lubricate and protect your water pump and fittings during storage. Close the outlet and turn the pump off.
De-winterizing: return to the road
- 1Fill your water tanks with water and flush the water system with freshwater. Note: Open all water release points (shower, sink, etc.). Make sure all the winterization fluid is flushed from the system.
- 2Follow the steps above to sanitize your potable water system.
- 3Turn the 3-way valve handle of the water pump in a horizontal direction (open position, Figure D).
- 4Turn the 3-way valve handle of the Truma into a horizontal direction (open position).
Your gray water system
Gray tank.
Open your gray tank drain valve and drain into an appropriate receptacle. Dispose of gray water responsibly at a dump station or drain point. Always check the rules for the state and campground that you are visiting to see what limitations may apply. Do not dump illegally. We recommend flushing your gray tank after dumping to help remove any unwanted build up. For best maintenance of your gray water tank do not allow dirt, debris, hair or other solid material to drain into the gray tank. You may want to dump your gray tank after your black tank and use the gray water to help wash residue from the black tank sewer hose.
To clean your gray water tank
- 1Fill your gray tank at least half way full with clean water. Add an RV gray water tank cleaning solution or tablet and follow the instructions for that product, or use dish soap or laundry detergent, 1/2 to 1 cup.
- 2Do NOT use bleach as it will corrode your tank, seals and gaskets. Any damage caused by using bleach is not covered under warranty.
- 3Take your OP15 for a spin to allow the gray water to slosh around and clean the inside of your tank and the tank sensors fully.
- 4You can then drain the gray water tank as above and we suggest rinsing it using a wand-style rinser afterwards.
- 5Following cleaning, use an RV gray water tank treatment to help dissolve grease and soap build-up and prevent odors. We suggest using a natural, biodegradable enzyme-based product that is formaldehyde-free such as Energen Gray Water Tank Treatment.
Winterizing gray & black tanks
- 1Fully drain and clean the gray and black water tank following the above steps. Close your drain valves after draining.
- 2Flush RV winterizing fluid down your bathroom sink, shower drain and toilet (without flushing; ensure the drain valve is closed).
- 3Winterizing fluid can remain in the tanks while in storage.
IMPORTANT! Monitor water temperatures closely in severe cold in case you must take the steps to drain and winterize your water systems whilst camping.
Your black water system
Black tank.
We recommend emptying your black tank when it is at least 1/2 to 3/4 full and after every camping trip. Emptying your tank sooner may result in solid waste being left behind in your tank; a fuller tank allows more opportunity for breakdown of solid waste. If you are on-site camping and connecting to a campground sewer we recommend keeping the tank's drain valve closed until you need to assist in purging the tank of solid waste.
Please use caution when emptying to avoid contact with waste which can carry harmful bacteria. The black tank must ONLY be disposed of in designated dump stations. Do NOT dump illegally and follow all state and campground guidelines for safe and clean dumping. Use the black tank drain hose stowed at the rear of the trailer in the holding tube to drain your black tank.
To empty your black water tank
- 1Remove the black tank hose from the storage tube by twisting the cap off.
- 2Connect the drain hose to the drain valve by twisting on to the receiver hooks.
- 3Ensure the other end of the drain hose is directed into the appropriate dump point.
- 4To empty, pull the valve to open.
- 5Leave the valve open until you can no longer hear liquid waste draining then close the valve completely.
To clean your black water tank
- 1Drain and dump any waste by following the steps above.
- 2Take measures to remove any build up from the tank walls. We recommend wand-style rinsers such as the Camco Swivel Stik that can be used with the toilet drain open to access the black tank.
- 3Use a treatment product to clean your black tank. We recommend using a biodegradable, eco-friendly product that is enzyme-based. Please take care to ensure your treatment is formaldehyde-free, as many dumping regulations now require this as standard. Follow the instructions on your chosen cleaning treatment to ensure the appropriate dilution as required. If you need to add water for your chosen product, you can do this by filling and flushing the toilet bowl several times.
- 4If your sensors are not reading accurately and flushing the tank does not resolve the problem, tank sensor cleaning products are available to help remove buildup.
- 5Your drain hose should also be regularly cleaned and sanitized.
Download the full user manual
It is all in
the manual.
For individual winterization, maintenance and care instructions please refer to the most recent version of your user manual.
Additional resources available in your manual
- 01Winterization
- 02Parts
- 03Greasing & servicing
- 04Battery storage
- 05New trailer maintenance
- 06Trailer brakes
- 07Seals, springs, etc.
- 08Suspension, wheels & hitch bolts
- 09Potable water tank
- 10Gray & black water tanks
- 11Weathering
- 12Zips & velcro
- 13Cleaning your tent
- 14Replacing an air beam
- 15Accessing inlet valve & inspecting leaks
- 16Customer responsibilities
- 17External care for your trailer
- 18Internal care for your trailer
- 19Storage / long term storage
- 20Battery maintenance during storage
- 21Service requirements
- 22Changing a tire
Not sure which steps apply to your build?
Water systems, heaters and battery setups differ across the range. Call the support team with your build year and chassis number, or ask your dealer to walk you through the first winter.