Key components of your RO system

To successfully troubleshoot your reverse osmosis system, you should first identify the root of the problem. The various parts of an RO system work together to provide clean water, so one problem could result from multiple components. Reverse osmosis troubleshooting requires a systematic approach to eliminate possible issues. Here's our guide on finding the right solution for your reverse osmosis system.
Filters: Prefilters provide sediment and chlorine protection. Sediment can damage or clog the flow restrictor. Chlorine can destroy the membrane material by oxidation. Postfilters provide a fresh pass through carbon on the way to your faucet, ice maker, or refrigerator.
Membrane: The RO membrane operates on pressure, which is the driving force that pushes water through the system. Without adequate driving force pressure, water production and TDS rejection will be negligible. Production rate varies based on feed pressure and water temperature.
Flow restrictor: The flow restrictor provides resistance to create driving force on the RO membrane while efficiently metering water flow rate to the drain. It's sized according to the membrane output rating and disrupts membrane output if not correct.
Check valve: The check valve is placed at the membrane permeate (filtered water) outlet. The check valve protects the membrane from back pressure and allows pressure to build with the tank filled, activing the ASO valve. Without it, the RO system will not shut down and could potentially cause membrane failure due to backflow. 
ASO (automatic shut-off) valve: This device monitors feed and tank pressures. When tank pressure reaches 2/3 of line pressure, the ASO valve hydraulically closes, stopping water flow.
Storage tank: Pressure tank (hydro-pneumatic) is the term used for the style of storage tanks used with RO systems. The tanks are divided into two chambers, one for water and one for air. As the tank fills with water, the separating diaphragm expands into the air side and increases the pressure on that side. This pressure pushes the water back out of the tank to the faucet or another point of use. Loss of pre-charge air pressure or diaphragm integrity can cause little or no flow at the faucet.
Drain saddle: RO systems have a flow to the drain that carries contaminants away. The waterline from the air gap faucet connects to the sink drain line with a drain saddle. 
Air gap: Plumbing codes require any cross connection (feed supply on one side, drain connection on the other) to have backflow prevention to prevent drain or sewage water from backing up into the drinking water supply. 
Feed pressure: The water pressure entering the RO system is crucial to the system's performance. It's important to consider the impact high levels of TDS and low pressure can have on a system's performance.