Basic Annual Service on Your Pure Water Products (Flowmatic) Economy Reverse Osmosis Unit

This is a step-by-step process. You don't have to follow this exact order, but it will be easier if you do.

1. First, check the TDS (Total Dissolved Solids) level of the unit if you have a tester. This is a test of the reverse osmosis membrane, not of the carbon filters. It measures ppm (parts per million, which is the same as mgl, or milligrams per liter.). The unit's product water should be about 1/10 the TDS of the tap water. For example, if your tap water has 500 ppm total dissolve solids, your RO unit should be running at 50 or lower. If you don't have a tester, take a guess. If the water tastes good, the membrane is probably OK. Membrane life depends on lots of variables, but a good RO membrane should last from two or three years to five or six. Call 940-382-3814 for other suggestions if in doubt.

If you're changing the membrane, go here for detailed instructions.

2. Assuming the membrane is OK, turn off the inlet water at the inlet valve to the unit. Turn off the tank valve at the top of the storage tank. Open the ledge faucet by pulling the handle up and leave it locked open. Wait one minute for pressure to go down.

3. Get the unit in a comfortable position (comfortable for you--don't worry about the unit) over a large pan if possible. A plastic dishpan works well. Putting a heavy towel under the unit also works well. It's often easiest to disconnect a fitting or two to get the unit into a comfortable workspace. Just remember how to put them back. Open the two vertical filter vessels (not the horizontal membrane vessel) using a filter wrench. The vessels screw apart in a counterclockwise direction. Remove the cartridges, discard them, and rinse out the vessels. Go on to step 4 unless you are replacing the membrane. If the membrane has to be replaced, disconnect the tubing that enters the cap. (The cap is on the end that has a single tube--the other end has two tubes.) Unscrew the cap. Usually, you can do this by hand. If a wrench is needed, a channel-lock pliers usually works well. When the cap is off, pull the membrane out. It isn't screwed in--just pull straight back. Some membranes have a pull ring, some don't. If there's no pull ring, grab the membrane stem or anything convenient with pliers and pull straight back. When replacing the membrane, handle with care. Touch it as little as possible (it's packed in preservatives, and you should also avoid contaminating it with bacteria from your hands). Wet the membrane with tap water to make it slide in easier, then insert it. IMPORTANT: Be sure it "hits bottom." To be sure, you can use a slight twisting motion as you push. If it doesn't seat properly, it won't work. Replace the cap and reconnect the tubing.

4. Replace the cartridges. The ERO uses radial flow cartridges. There is no up or down. Lubricate the O-rings in the vessels lightly if they feel dry. Silicone grease is the ideal lubricant. Be sure that the O-rings are properly seated in their grooves. Screw the vessel sumps back onto their caps. Tighten snugly, but don't overdo it. (Over-tightening can damage O-rings.)

5. Next, replace the horizontal post filter that is clipped to the membrane housing. Be sure to observe the direction of flow on the old unit before removing it. You'll have to remove the tubes that connect the filter to the RO unit, remove the fittings from the old filter, retape the threads of the fittings with teflon tape, and reinstall them into the new filter. Reinstall the new filter on the unit.

6. After reconnecting any tubing you have removed, slowly open the inlet valve and let water into the unit. Check for leaks. It is normal to hear lots of gurgling and hissing as air escapes down the drain. Next, with the ledge faucet still locked open, open the valve on top of the tank. Water will now leave the tank and exit through the open faucet. It is normal for a heavy black discharge (caused by carbon "fines" from the new post filter) to come out of the faucet. Let the tank drain completely. It may take some time. It will finally become a fast drip. The drip is the unit's production--the amount of water that it produces. It should be a fast drip or a small stream.

7. Now, pick up the storage tank. If it is empty, very light, close the faucet and let the tank refill. If it still has water in it--and this is usually the case--attach a bicycle pump to the air valve on the tank. On the ERO, the air valve is located on the side near the bottom of the tank. You may need pliers to remove the cap. With the faucet still open, pump air into the tank. Water will start to leave the tank through the open ledge faucet. Continue to pump air into the tank slowly and steadily until all water is out of it. The faucet will return to a fast drip. Try to leave about 7 pounds of pressure in the empty tank. If you don't have a low-pressure gauge, guess. The exact amount isn't that critical. Don't over-air the tank, however, because you won't be gaining more pressure; you'll just be leaving less room in the tank for water. Note: With some pumps it is virtually impossible to connect to the Flowmatic tank without a valve stem extender. These can be purchased at any auto parts store.

7. When the tank is aired, close the faucet and let the unit refill. You're through. You'll have enough water to use in a few minutes, but it may take a few hours for the tank to fill completely.

Don't hesitate to call for help. PURE WATER PRODUCTS (940) 382-3814. Or email pwp@pwgazette.com

Back to Products Index Page.