Installing a Reverse Osmosis System

  • 01 of 10

    Installing a Reverse Osmosis System

    Reverse osmosis water filter
    Photo © Aaron Stickley

    An under sink water filter is a convenient way to get good tasting drinking water at home. A reverse osmosis system is one of the various options available for water filtration in the home. With a little preparation and planning installing a reverse osmosis system can be fairly straightforward.

    From preparation to pressure testing the following steps walk you through installing a reverse osmosis system.

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  • 02 of 10

    Preparation

    Reverse Osmosis System Measurements
    Photo © Aaron Stickley

    Before purchasing a reverse osmosis system you might want make sure that there is enough space under the kitchen sink for an RO tank and filter system. Take a look at the area under the sink and take some measurements of the available space.

    Also, make sure you have an idea of what cold water source can be used. Most units come with a tee connection that comes off of the 1/2" supply line going to the faucet. In some cases there is a 3/8" flex line that comes down from the faucet. In that...MORE case an adapter tee above the shut off valve can be used to provide a source of water for the reverse osmosis system.

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  • 03 of 10

    Planning

    Reverse Osmosis Layout
    Photo © Aaron Stickley
    Unbox the storage tank and reverse osmosis assembly and double check that they fit under the kitchen sink in the desired locations. I like to set all of the components in place just in case any adjustment need to be made to the drains, pipes or anything else before installing the RO system.

    Most of reverse osmosis systems go under the kitchen sink but they can be installed in a remote location like the garage after the water softener and then run back to the faucet. Remote installation does not...MORE take up any room under the sink but it does require more work to install. Planning: Unbox the storage tank and reverse osmosis assembly and double check that they fit under the kitchen sink in the desired locations. I like to set all of the components in place just in case any adjustment need to be made to the drains, pipes or anything else before installing the RO system.

    Most of reverse osmosis systems go under the kitchen sink but they can be installed in a remote location like the garage after the water softener and then run back to the faucet. Remote installation does not take up any room under the sink but it does require more work to install.

    Continue to 4 of 10 below.
  • 04 of 10

    Install The Faucet

    Reverse Osmosis Faucet Installation
    Photo © Aaron Stickley
    Install the faucet first so you can get the lines down under the sink before it gets too crowded beneath the sink. Mount the RO faucet housing to the kitchen sink with the hardware provided. Feed the water line down and connect the air gap (red tube) into the faucet before locking the faucet down onto the housing.
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  • 05 of 10

    Tank

    Reverse Osmosis Holding Tank
    Photo © Aaron Stickley

    Before putting the RO tank into position under the sink install the tank connector. Apply plumber's tape onto the threads of the tank nipple. Screw the connector onto the tank making sure to avoid cross threading. The connector only needs to be hand tight and should thread on easily.

    Now you can put the tank in place. The yellow tubing is what hooks up to the tank in a later step.

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  • 06 of 10

    Filter Assembly

    Reverse Osmosis Assembly
    Photo © Aaron Stickley
    Remove the filter assembly cover and mark the locations for the hanger washers on the wall using a level to ensure that the unit is straight. This assembly needs to be a minimum of 15 1/2" from the floor to allow enough room to remove the filters.

    Screw the hanger washers onto the wall at the marked location and then set the assembly on the washers.

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  • 07 of 10

    Water Line

    Reverse Osmosis Water Line
    Photo © Aaron Stickley

    The green 1/4" water line needs to be hooked up to the water supply line. In this example I could not use the 1/2" adapter because the faucet has a 3/8" flex line build in. What I did is shut off the water at the straight stop and installed an adapter tee that was 3/8 x 3/8 x 1/4 so I could hook the faucet back up and then have a 1/4" line for the green feed tube. I hooked up the green line with a nut, ferrule, and insert.

    Note: Be sure to turn off the water supply before...MORE connecting the water line to the reverse osmosis system.

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  • 08 of 10

    Connect Tubing

    Reverse Osmosis Tubing
    Photo © Aaron Stickley
    When connecting the tubing use the extra length of the tubing to your advantage and run it to the back of the cabinets or as necessary to allow for the cleanest installation. I like to leave extra tubing so I will have the extra tubing if the reverse osmosis system needs to be moved at a later date. Tubing can also be trimmed to size for a nice clean look if you prefer.

    For this particular reverse osmosis system the yellow tubing goes to the storage tank, the blue tubing will push into the R.O....MORE assembly (larger side), and the black will push into the drain adapter kit. Before connecting the yellow tubing follow the manufacturer’s instructions about sanitizing the system.

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  • 09 of 10

    Drain

    Reverse Osmosis Drain
    Photo © Aaron Stickley

    For the whirlpool reverse osmosis system a drain tee is included. Just set the tee up to the existing pipe then mark and cut the pipe. Make the cuts to ensure that the tee fits tightly. The nuts and washers are easy to hand tighten; just like putting in a continuous waste. Screw the drain end on using the nut and washer. Push the black drain tube into drain adapter tee.

    Note: The drain tee would normally install in the vertical position but instead I installed it on a horizontal run because there...MORE is no room for it on the vertical drain pipe.

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  • 10 of 10

    Pressure Test

    Reverse Osmosis Faucet
    Photo © Aaron Stickley
    Turn the water supply on and open the cold water on the sink to get any extra air out of the pipes. The pressure will start to build up in the reverse osmosis system and you will have to wait for about 2 hours to get full pressure. Check all of the fittings and tighten any that are loose or leaking.

    You should drain the system by leaving the reverse osmosis system faucet on and allowing it to empty out and purge completely for 24 hours before drinking. The water will be a slow trickle after the...MORE tank is empty. Just leave it on for 24 hours. Continue to test for leaks during this time.