Noticed that my waterfall wasn't working. Checked the pump and pressure and noticed the pressure was 5psi higher than normal. Removed the cartridge filter and retried. There was no change. No change to any valve position.
After the filter, the water flows to a heater, then to an in-line chlorinator. After that it flows back to the pool. Closing the return valve allows the waterfall to work.
wondering how to troubleshoot the loss of flow and increase of pressure