Servicing the SQC3 Reverse Osmosis System

Purpose

To change the RO filter cartridges, and clean and sanitize the system.

Tools and Supplies Needed

• Pre and post filter. The prefilter has a yellow dot on the top and is called a "Sediment/Carbon Cartridge". The postfilter has no color dot on top and is called a "Carbon Cartridge."
• Catch pan - to catch the water that tends to spill when removing old filters and the various water lines that connect the different parts of the system.
• Chlorine - for sanitizing (plain, unscented Clorox is best).
• Paper towel or a clean cloth or rag.
• TDS hand held tester and clean cup.
• Bicycle pump
• Air pressure gauge (you need a good one that can measure accurately in the 5psi range - the ones for cars that are pencil shaped will not work)
• ¼" tube approximately 2 feet long
• 3/8" tube about 1 foot long
• 1/4 x 3/8 union fitting

Procedure

Please note: The *, **, etc. all indicate further notes. These are found at the end of the Procedure list.

1. Perform TDS test on RO water (to verify membrane function ***). Do this by filling a cup with about 1-2 ounces of water. Turn TDS tester on. Put TDS tester in the water to about 1" depth. Record the TDS value. Empty the water and fill the cup with tap water. Do the TDS test again and remember the TDS value.
2. Verify that the shut off valve is working. If your RO has been installed in a standard manner, the faucet will also act as an "air gap" and when the unit is operating, there will be a small stream of water flowing through the hole under the faucet handle.
   • Check to see if water is flowing - if not, the shut off valve is working fine.
   • If it is flowing, shut off the valve on top of the the storage tank. Then, watch to see that the flow slowly comes to a slow drip or stops altogether. If this flow does not stop, either the shut off valve is malfunctioning or there is another problem with the system and you will need a service call by a professional.
3. Turn off water supply to the RO at the supply stop or the valve at the end of the orange tube.
4. Turn off valve on top of the storage tank.
5. Open RO faucet to relieve pressure.
6. Remove yellow line from valve on the storage tank ** (Have catch tray ready to catch dripping water from line once it is removed).
7. Remove storage tank and drain all its water into sink by opening valve.
8. Test the pressure of the tank - maintain at 5-7 psi. Pump more air in if necessary.
9. Sanitize the tank. Do this as follows.
   • Connect 3/8 tube to valve at tank. *
   • Disconnect orange line ** at the RO assembly inlet and connect to 1/4 x 3/8 union fitting *.
   • Carefully pour about 1 tablespoon of bleach into the 3/8" tube that you've connected to the tank valve and keep that tube raised so the bleach stays in.
   • Connect the union fitting with the orange tube to the 3/8 tube with the bleach. *
   • Turn on water at supply stop to fill the storage tank; make sure tank valve is open.
   • Once the storage tank is full -- it will take several minutes -- turn off the supply line, turn off the tank valve and disconnect the tubing. ** This will be more difficult because the line is under pressure and you will get a little bit of water spitting out.
   • Remove union fitting from orange line, and 3/8 line from tank valve. **
   • Reconnect the orange line to the inlet connector, and the yellow line to the storage tank. * Leave the tank valve closed for now.
10. Remove pre and post cartridges on either side of the membrane by turning them 1/4 turn counterclockwise (edge of cartridge closest to you will move to the left) and then pull straight down. (Can be done while storage tank is filling - have catch tray positioned underneath the filters.)
11. New filter cartridge installation
    • Install the new cartridges - label faces to the front of the unit.
    • Drop only 2 drops of chlorine into the pre-filter only, before installing to help sanitize the membrane.
    • Push cartridges up, then turn 1/4 turn clockwise until they stop turning.
12. Remove red tube in back of the membrane ** and connect the ¼" line. * Hold the other end so that it is directed into the sink.
13. At this point, turn on water at supply stop while holding the 1/4" line. What happens is that water in the membrane will pass through the ¼" line followed by a burst of air, and then more water with some carbon particles in it. This is done to 'blow' the system of air and then carbon 'dust' from the new pre-filter. The membrane appreciates this.
14. Once you see the water beginning to go through the line, turn off the water at the supply stop.
15. Allow any water in the ¼" line to drain out, disconnect that line from the back of the membrane, ** and reconnect the red line to the back of the membrane. *
16. If you have a monitor, check the batteries with a battery tester and replace if necessary.
17. Open supply stop to run water into system and pressurize it. (All lines are connected at this point, just the way it was before you began the service procedures.)
18. Next, open the faucet, and then open and close the storage tank valve a few times to let air out of the line. Do this until only water is flowing. Close faucet and tank valve. Let system stand for several minutes.
19. Look for leaks **** at connections where you disconnected and reconnected lines, and at the filter cartridges.
20. Open the faucet and tank valve again and let all the water drain out of the storage tank. Don't drink this water or give it to your plants. When the flow has slowed to a trickle, shut off the RO faucet only.
21. Let the storage tank refill with water. This will take about 4-5 hours. Then drain this water. Again, don't drink this water or give it to the plants.
22. After this, your storage tank will again refill with water. This water is good to drink. Your system is now back to normal.

* Making connections with the quick connect fittings that come with your SQC3 RO system:

• Push the tube into the fitting about 1/4-3/8". You will feel it bump up against a "stop"
• Push the tube an additional about 1/4-3/8". It will push past that first stop and then bottom out at a second stop. It is now inserted correctly.
• NOTE: if you don't get the tube to the 2nd stop, it will leak **** a lot.

** Disconnecting water lines (tubes) with the quick connect fittings that come with your SQC3 RO system:

• Push the line towards the connector, grab hold of the plastic "collet", and then pull the line away from the connector. It should disconnect easily. If it doesn't, make sure you hold the collet tightly against the connector and pull the line a little harder.
• NOTE: the difficulty always occurs because the collet isn't held tightly against the connector body.

*** Interpreting the TDS results:

• The TDS tester measures total dissolved solids in the water. The RO membrane is functioning when the TDS reading for the drinking water from the RO faucet is less than 25% of the TDS reading of the tap water.
• For example, the TDS for the drinking water is 35 and the reading for the tap water is 300. The membrane is functioning as it should. However, if the TDS for the RO water is 75 or above, then the membrane is considering to be ineffectively functioning and needs to be changed. Call a water technician for this job, and wait to change the filters until the membrane is changed.

**** What to do if you find a leak:

• Make sure that the water line (tube) is correctly inserted into the fitting. Sometimes, it isn't pushed in deeply enough, even though it felt like it was.
• If that doesn't work, then jiggle and push the line in the fitting. Sometimes this works.
• If not, then reposition the equipment (usually the storage tank) in the position it was before you began servicing the system. Then repeat the above steps.
• If that doesn't work, call us. The fitting probably needs to be rebuilt.

 

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