The reverse osmosis system use filters and RO membrane to purify water. Both membrane and filters do not last forever after treating water for sometimes they require replacement for the system to operate effectively. In this article learn step by step how to replace Reverse osmosis filters and membrane
When to change reverse osmosis filters and membrane
A standard under sink reverse osmosis system treats water in four stages. Each stage has a different cartridge that your contaminated water passes through. The filters involved in each stage include:
Sediment filter: this is the first stage that removes particulates. The filter is changed every 6 to 12 months
Carbon pre-filter: This is the second stage that removes chlorine taste and odor. The filter is changed every 6-12 months
RO membrane: This is the heart of the system that removes heavy metals and TDS. The membrane is changed every 2-3 years
Carbon post-filter: this is the final stage and polishing stage that helps remove any remaining taste and odor. The post-filter is replaced every 6-12 months.
Step by step procedure how to replace Reverse osmosis filters
- Make sure you have all required replacement filter and membrane
- The replacement filter and membrane should remain in their original package until they are ready for installation.
- Make sure your hands are clean
- Turn off the water supply
- Turn off the storage tank valve
- If you have a line going to the refrigerator or icemaker from your RO system make sure you turn off
- Open the RO faucet to drain off all water in the system
- Unscrew the housing and remove old membrane and filters from their housing. If you have a problem unscrewing the housing use wrench to assist with that
- At this point clean the housing using dish soap and clean warm water. You can sanitize the housing using unscented bleach. Rinse the housing thoroughly.
- Check for O-Ring whether in the right condition. If not in good condition replace it with a new one. Lubricate the O-ring with silicone lubricant. O-ring provides a tight seal between the housing and housing cap. This help prevent leaks
- Add new filter or membrane to their respective housing
- Return the housing to the system. You can use a wrench to tighten the housing but make sure do not over-tighten. Over tightening can flatten O-ring and crack the housing leading to a leak.
- Turn on water supply and RO faucet (at this time no water is entering the storage tank remember it is still on bypass mode)
- Check for leaks and let the system flush for few minutes.
- Turn off RO faucet
- Turn on the storage tank valve
- Wait for the tank to refill
- Discard 2 full tanks of water before but this depends on the system. You can use water for watering plants or cleaning
RO membrane replacement procedure
- Repeat steps 1 to 7 above
- Remove the tubing from the membrane housing cap
- Remove the old membrane from the housing
- Clean the housing using warm soapy water and rinse thoroughly
- Insert new membrane into the housing and make sure O-ring are in place and in good condition
- Return the membrane housing to the system
- Reinstall back the tubing. Ensure the tubing are securely connected
- Continue with steps 13 to 18 above