How to change Kinetico K5 filters

Read the PureMometer and go by the calendar too. The K5 has a PureMometer, a blue gauge at the top of the unit above the MACguard postfilter that shows how much filter capacity remains. Kinetico says that when the gauge is about three-quarters of the way up, the postfilter is at full or near-full capacity. When it's below halfway, the filter is close to the end of its useful life and a change is coming soon. At or near the bottom, you can change the cartridges before flow at the faucet slows dramatically or stops.

Kinetico also gives a calendar rule. You should replace the filters each year, or when the flow of reverse osmosis water slows or stops completely, whichever comes first. You may also need to change them after a boil order or another event that can compromise them. All Kinetico drinking water filter cartridges are designed and rated to filter 500 gallons of water.

Two details help. First, when the PureMometer says the postfilter needs changing, all the K5 filters should be changed at the same time. Second, if the water is slow or stopped and the gauge is low, that combination confirms a change is needed.

The EPA makes the same general point about home treatment units. It says all units need some maintenance, that you should follow the manufacturer's recommendations for replacement and that activated carbon filters are designed to filter a certain amount of water, after which they clog and become ineffective. A filter left in past its rating isn't doing the job you bought it for.

Kinetico says the K5 uses three standard filters: one to remove chlorine, one to remove contaminants such as metals and nitrates and one to eliminate compounds that cause foul tastes and odors. Its standard set includes a sediment prefilter (two options), the reverse osmosis membrane and a postfilter. Here's how Kinetico describes each:

• Sediment prefilter. Reduces sediment during prefiltration. Kinetico says it's commonly used for well water.
• High capacity carbon/sediment prefilter. Reduces sediment and chlorine. Kinetico says it's most often used for municipal supplies or water treated with chlorine.
• Reverse osmosis membrane. The heart of the system and exclusive to Kinetico. It isn't a FlexFilter and doesn't need regular replacement.
• Taste and odor postfilter (MACguard). Reduces tastes, odors and aesthetic chlorine before you drink the water.

Kinetico also lists optional cartridges you may have: a Perchlorate Guard, a Purefecta Guard, a VOC Guard (standard on the K5 with VOC Guard), a Mineral Plus additive cartridge, an Arsenic Guard and a Chloramine Guard. If you use any of these auxiliary FlexFilters, Kinetico says a filter change is the best time to replace them too, and it suggests testing your water with a local Kinetico expert before making filtration changes.

Keep a replacement set on hand. Kinetico suggests it so you never go without RO water because you weren't ready for a change.

Sanitize the system first, and wash your hands. If you change the filters yourself, Kinetico says you need a sanitization kit from your authorized independent Kinetico dealer. Wash your hands thoroughly and don't touch any K5 internal mechanisms or parts. Then follow the instructions that come with the kit to disinfect the system. Kinetico's instructions don't reproduce the kit's steps, so use the paper that comes with yours.

Also confirm you have the right cartridges. The inside of the side panel carries a guide showing where each filter goes, so check what you bought against that guide and against the cartridges currently in the unit.

These are Kinetico's seven steps, with the details it gives.

1. 1Shut off the water to your K5. Find the on/off valve for the drinking water system and turn it off. Kinetico's warning is blunt: skip this and your home, and you, will get wet.
2. 2Depressurize the system. Open the dedicated K5 faucet and wait until the water has drained and only a drip is left. If the system already shut off flow at the faucet, no water will come out. Then close the faucet.
3. 3Remove the side panel. Open it and verify you have the correct replacement filters. Replace all filters at the same time, but not the reverse osmosis membrane.
4. 4Replace the cartridges. Turn each old cartridge counterclockwise about a quarter to a half turn, until the ridge at the top reaches the notched opening, then pull down. Expect the cartridge to be full of water and the system to dribble. Fit the matching new cartridge with its ridge in the notched opening and turn clockwise until it locks. Repeat for each filter. For the MACguard postfilter, the small hole at the top center must engage the PureMometer pin. Push up, and the blue gauge should rise about three-quarters of the way in its window. You'll feel it seat fully before you lock it.
5. 5Replace the side panel. Line it up so the magnets engage.
6. 6Turn the water back on slowly. Check the filters for leaks. If one leaks, shut the water off, tighten that filter a little more and try again. The K5 faucet won't dispense until the shut-off valve is open.
7. 7Flush the system. Let two storage tanks of water run through the unit. Slowly open the K5 tap, and let it run until the stream stops. The water may sputter because air got into the lines. Wait several minutes for the tank to refill, then flush a second time before you drink any of it.

Once the second flush is done, you're back on RO water.

### Do dealer instructions match Kinetico's?

They can differ on details. One Kinetico dealer's one-page guide tells owners to fill the new prefilter with water and to let the unit refill for at least two hours before use. Kinetico's own K5 page doesn't say either, and it calls for two tank flushes instead. Follow the manufacturer's page, or ask your own dealer which they prefer, because dealer practice can vary.

Either works, and Kinetico supports both. Kinetico says having its dealer perform the sanitization and filter change ensures the system is properly cared for, and it gives you the DIY steps if you prefer. A DIY change still starts with a stop at a dealer for the sanitization kit. HQ Plumbing & Air can help with the plumbing around the unit, such as a leaking shut-off valve or supply line. We're licensed and insured, give free estimates and quote an upfront price. For the softener side of a Kinetico system, see whether a Kinetico water softener uses electricity and what salt a Kinetico softener uses. If you're comparing an RO system with softening, reverse osmosis vs. a water softener covers what each one does.

For the softener's own sediment filter, see how to change a Kinetico softener prefilter. After a boil water notice, see what to do with a softener or RO system during a boil water advisory.