The answer to 'water softener slow draining' is that a slow draining water softener is often caused by a clogged or malfunctioning drain line. This can happen due to mineral buildup, debris, or a kink in the drain line. Symptoms may include slow or sluggish water flow, water backing up into the softener, or the softener not regenerating properly.
To troubleshoot, first check the drain line for any clogs or obstructions. You can try flushing the line with a garden hose or use a plumber's snake to clear any blockages. If the drain line seems clear, the issue may be with the softener itself, such as a faulty valve or other internal component. In this case, it's best to call a professional plumber to diagnose and repair the problem.