I recently replaced the filters in my under-sink Reverse Osmosis (RO) system, which has four filters. After changing them, I went from having low water pressure to completely losing all pressure. The filters are in the correct order now, but when I connect the Thin Film Composite Membrane, water isn't flowing to the last filter or coming out of the system at all. I'm looking for a quick and inexpensive way to fix this issue, if possible.
2 Answers
You might want to check if there's air in your pressurization tank. I had a similar issue, and that was part of the problem. Mine was sitting at 6.5 psi, which could be affecting the flow. It’s worth a look!
How long has it been since you last changed the filters? When I did mine, the technician mentioned that it can take up to four hours for the system to fully cycle after a replacement. Also, it’s important not to drink the water before that process is finished. Just something to check!
I haven't changed them for multiple years—definitely more than 5! Now that I’ve replaced everything, the system stopped leaking, but I'm still not getting any water when I turn on the tap.

I have air in the tank, but when I install the filters one at a time, they allow water to pass to the next, until I reach the thin film membrane. After that, it just stops and starts leaking from the filter before it.