The membranes can be tough to remove due to the tight fit of the 'o' rings.

Turn off the water supply to the unit and disconnect the hose from the inlet side of the membrane housing. The housing can then usually be unclipped from the top of the RO unit, in some cases it may be necessary to remove the two hoses coming out of the membrane housing. If this is the case make sure you take note of which connection is for each hose. The membrane housing will still be full of water so be aware that water may come out of the connections as they are undone.

Unscrew the end cap from the membrane housing, making sure not to lose the 'o' ring. Using a pair of grips or large pliers pull on the plastic end that sticks out of the membrane, sometimes turning it as you pull will help to release it if stuck.

Once the old membrane is removed inspect the inside of the housing to make sure the end where the membrane pushes into is in good condition and wipe away any sediment that may have been deposited with RO water and a bit of paper towel.

Remove the new membrane from its protective bag and install it so that the end with the two black sealing rings is inserted into the housing first. This should be pushed tight into the tube until the other end of the membrane is almost level with the top of the threads. It should be a snug fit. Screw the end of the membrane housing back in to place, making sure the 'o' ring is positioned correctly. Then clip back on to the RO unit and re attach the hoses.

When replacing the RO membrane it is good practice to replace the carbon and sediment pre filters along with the flow restrictor on the waste water pipe.

If replacing the carbon prefilter, before turning the water on for the first time, disconnect the hose going in to the membrane housing and aim it towards a suitable bucket and turn on the water supply. This will then flush water through the prefilters into the bucket removing any dust from the carbon block. Once flushed turn off the water supply and reconnect the hose to the membrane housing.

Disconnect the DI resin pod, if using, from the RO outlet and turn on the water supply. The membrane will need to be hydrated and flush before collecting the water produced. Leave the unit running with the tap of the flow restrictor fully closed, normal operating position, and dispose of the first 5-10L of RO water produced. After this the DI resin, if used, can be reconnected and the RO water collected for use.

Please be aware the TDS may initially read high, even after flushing. This is due to air trapped in the material of the membrane, this will cause Co2 to be dissolved into the water resulting in the TDS meter reading incorrectly. Once the membrane has been run for a period of time this air will disperse and the TDS will read correctly.