The answer to 'water softener making gurgling noise' is that a gurgling sound from your water softener is typically caused by air being trapped in the system. This can happen for a few common reasons, like a problem with the brine tank, a clogged valve, or a malfunctioning control head. The gurgling noise is usually not a serious issue, but it's a sign that something in the softener needs to be checked and addressed.
First, try to identify the source of the air getting into the system. Check the brine tank to make sure it's filled with water and the float is working properly. If the tank is empty or the float is stuck, that could be allowing air to get sucked into the system. You can also try cycling the softener through a regeneration cycle to see if that clears out any blockages. If the gurgling persists, it's best to call a professional plumber to inspect the softener and diagnose the root cause.