A widely common problem people have with their water softeners is too much water going back to the brine tank after regeneration. This can happen with a 15 year old softener or a brand new one. There is likely only one cause; a leak somewhere. Finding that leak is the trick. So if you’ve searched and found this article, you have a problem with your softener’s brine tank over filling. Therefore, you do not want to have to read through the mechanics of the brine system of your water softener, you just want to fix it. So I will try to get right to the point here.

First of all, if your water softener is brand new, the leak is not caused by your brand new control valve. Do not bother to call whomever you purchased it from and demand a warranty replacement. You will still have the same problem with a brand new controller. The leak is likely in the line leading from the control valve to the brine tank. There are only two fittings in this line, so check both of those. Even the plastic fitting inside the brine tank’s brine well needs to be “wrench tight” not finger tight.

If your water softener is older, say 2 or 3 years, then it’s likely you need to clean the brine injector assembly and the air-check at the bottom of the brine tank’s brine well. The brine well is a large diameter tube that runs down the inside of the brine tank. The air-check will be in the bottom of that. If you have an Autotrol model 255 control valve, you will not have an air-check in the brine tank, but there will be a brine pickup there which should be checked and cleaned of any debris if necessary.

The air-check is simply a plastic ball in the bottom of a serrated tube. The ball closes off the backflow of brine water out of the brine tank. In other words, the control valve does not “know” when the brine tank is empty. This air-check mechanism takes care of sealing off flow from the brine tank. If it does not seat properly, there will be a vacuum leak. The service manuals of all makes and models of water softeners we carry deal directly with cleaning of these air-checks and brine injectors. After making sure the brine line is not leaking, the air-check and brine injector are the next items to focus your attention. They should be clean of any brine or debris buildup.

Finally, all water softeners sold by Water Value come with a safety overflow float assembly. If yours has a leak where the brine pickup tube connects to the safety float shutoff, you will eventually end up with an overfilled brine tank. If the safety shutoff valve itself is leaking, you will also end up with an overflowing brine tank. Check that pickup tube and float assembly for leaks. A very easy way to do this is to activated your safety shutoff valve when the water softener is in brine refill mode. Simply pull up on the float assembly rod to activate the shutoff. If you see water dripping out, then you have a shutoff valve leak.

If a control valve has a brine draw cycle time of 8 minutes, and there is a vacuum leak somewhere in the brining system, that 8 minutes might not be long enough to draw all of the brine water out of the tank and into the softener’s resin bed for regeneration, leaving some brine in the brine tank. Then when the control valve reaches its final brine refill cycle, it will run for 8 minutes to replace the water it initially drew up out of the brine tank. If the brine tank still has water inside because of the vacuum leak, too much water will be sent to the brine tank. This is what causes brine tank overflow. It’s also possible that it could take several regenerations over several weeks time to realize this condition.

The preventive maintenance section that comes with these softener systems’ service manuals explains how to clean your specific brine valve and air-check. Do this brine system cleaning once per year, and you should never have brine tank overflow problems again.