MSR MiniWorks EX Maintenance and Troubleshooting

The MSR MiniWorks EX requires regular cleaning and maintenance to function properly. Cleaning and maintenance depends on frequency of use and water quality. The Ceramic Element will clog gradually during use, especially when filtering from glacial streams or cloudy water. If necessary, replacement parts can be found online on our website or purchased separately from a local or online MSR dealer.

For more information, check out our blog post on maintaining your MiniWorks filter. 

What are the materials in the EX filters?

The Marathon ceramic element is made from diatomaceous earth that's heated to the point where it just begins to melt. Most particles are caught within about .005 inch of the surface. When it clogs, you abrade away the clogged pores, making them immediately ready for more use, with almost 100% recovery after each cleaning. Marathon ceramic provides long-lasting protection from protozoa and bacteria. A block carbon core reduces tastes, odors, some chemicals, and many pesticides. The WaterWorks microfilter also incorporates a PES (polyethersulfone) membrane filter, which passes the test for a sterilizing or pharmaceutical-grade filter. It serves as a safety net, providing a second fail-safe seal.

How long will my ceramic filter last?

How long a filter lasts will vary radically from one water source to the next. The ceramic element can last up to 2000 liters. Filter-life ratings are based on best-case scenarios because the testing is performed with clean lab water. Generally you can assume that your filter will last between 50 and 100% of the rated life.

How much water will my filter pump before clogging?

Normal conditions may allow a user to filter between 10 and 20 liters between cleaning. Please note that water quality varies a lot with the season and water source. In general, the more turbid (cloudy) the water, the more frequently your filter will require cleaning and eventually replacement.

Why is the handle on my filter so hard to push?

There are three possible causes of this. The most likely is that one of the microfilters is clogged. Review the instructions for cleaning the ceramic filter. The PES membrane (WaterWorks microfilter only) may also be clogged. It will have to be replaced or removed altogether. Lastly, the piston O-ring may be very dry, causing friction. Lubricate it with the silicone lubricant provided in the maintenance kit (or use lip balm or petroleum jelly).

Why is the handle on my water filter so hard to pull?

If the handle is hard to pull, something is obstructing the flow of water into the filter. Clean the inlet foam and remove any kinks in the inlet hose.

Why does the handle on my filter feel limp when pumping?

The most common reason for a limp handle is dirt under the umbrella valve. Refer to your instruction manual for more specific part schematics or visit our MiniWorks EX product page and select "FAQs and Documents.". Remove the head of your water filter to expose the umbrella valve. Rinse under it or pull it off, rinse, and reinstall.

Why does my filter squeak when I am pumping?

The squeaking you hear is probably caused by actuation of the pressure-relief valve. This valve is designed to release when there is excessive pressure. Water goes back out the intake hose so you stay dry. You can tell if your relief valve is releasing by watching bubbles in the intake hose—if they go back and forth when you pump, the relief valve is working. It may be time to clean your ceramic filter (reference your owner's manual for complete details), or maybe you are pumping too fast. Do not pump faster than one stroke per second for best efficiency. Older MSR filters sometimes squeak in the pump head, piston pins, and bushings. You can eliminate the squeak with a tiny dab of lubricant on these parts. Newer MSR filters have the lubricant molded right into the pins and bushings, eliminating the squeak.

How should I store my MiniWorks filter?

Remove the ceramic element and air dry for 3–5 days. This will prevent growth of mold, mildew, and bacteria. Wash and dry other filter parts thoroughly before long-term storage. It never hurts to follow the sterilization process below!

I forgot to dry out my filter before putting it away—what should I do now?

The ceramic cartridge, which comes as standard equipment in the WaterWorks and MiniWorks, can be boiled to kill bacteria that may grow in it. Remove the filter base o-ring before placing the cartridge in boiling water. Always let the water cool down before removing the ceramic cartridge from the water. Removing it early can damage the plastic end caps. (Cold water can be added to the hot water to speed this process.) Dry thoroughly before storing.

What happens if my filter freezes?

If you anticipate that you will encounter freezing temperatures, make sure you drain the filter of excess water after each use to protect it from damage. If the filter does freeze, bring it inside the tent or other warm place to thaw, or follow the directions (in the instructions) for boiling the cartridge. Check the filter for any cracks.