Softening / Softener Difficulties

Tips can help with diagnosing and understanding three key problems.

By Mike Hamberger from the June 2001 edition of Water Technology magazine.

A weak or no-brine draw causes poor capacity, salty water or hard water to the home. To correct the problem, first check the normal areas that affect the brine draw of a unit, such as: a plugged injector and screen; low inlet pressure to the unit; restrictions in the drain line or backwash flow controller; and the compression fittings on the brine line for air leaks. Cycle the control valve in the brine draw position and observe the water flow at the drain.

1. A weak flow at the drain can be caused by any of the following: the passages in the control valve that feed water to the injector screen or that exit the injector to the mineral bed may be restricted, due to iron fouling or debris; the slotted area in the lower distributor basket may be fouled with debris; or if the control valve has an “upper collector/basket,” the slotted area may also be fouled with debris. The second two reasons would also cause a poor flow rate and low pressure to the home when it is in service.

2. A high flow at the drain can indicate that if the injector assembly was not replaced but looked clean, the nozzle portion of the injector may have worn larger than its original size.

The nozzle side of an injector is typically one-half the diameter of the throat opening. Since the nozzle creates a high velocity, it can be subject to wear and become out of tolerance. If the injector assembly comes as two separate items, replace both as a set.

An internal leak inside the control valve could also cause the problem. In the brine draw cycle, all the flow is directed through the injector assembly. An internal leak in the control valve will allow excess water to bypass the injector and put back pressure on this assembly.

A quick and easy way to check for internal leaks would be to take a spare injector assembly (nozzle only for a two-piece type) and physically plug it so no water can pass through it. You can melt the nozzle tip shut or take a hot glue gun and seal the nozzle. Install this modified assembly back on the control valve and cycle it back into the brine draw position. A flow of water at the drain indicates an internal leak in the control valve.

For control valves using a piston/seal operation, check the piston for scratches and/or replace the pacer/seal assembly. For control valves using a flapper type operation, the inlet and outlet flappers must completely close during the brine draw cycle.

3. A normal flow at the drain. On some control valves, an “air disperser” is part of the brine injection system. This is located after the injector assembly as the brine enters the valve body and could be dislodged during the repair service of a system. Its purpose is to keep the injector throat rimed during brine draw if air gets into this assembly.

Hard water bleed after a system has regenerated. Make sure to check the following: the bypass valve is in the full service position; the salt and water levels in the brine tank are at the proper levels; there is a good suction from the injector assembly; and the unit is set up properly for the water conditions and the number of people in the family.

If these conditions are fine and you still test a few grains of hardness on the softened cold water side, there is a possibility of a pinched or nicked distributor o-ring on the valve. There could be a defective distributor tube (the top section that fits into the valve is nicked or distorted) or the distributor tube has partially come out of the valve (hot water from the water heater has backed up into the valve).

For a quick way to check for this without removing the control valve from the tank: cycle the valve into the brine draw position and taste (or use your total dissolved solids (TDS) meter) the water at the drain. If the water tastes salty (or the TDS increases rapidly) after one to two minutes, there is a possibility of a defect in the valve distributor pilot o-ring or distributor tube.

Under normal operation it should take 10-15 minutes for the brine to pass through the resin bed and discharge to the drain.

Running short of softening capacity. You have checked the system set up vs. water conditions and family size, but that hasn't led to the cause of the condition. A number of conditions can cause this situation.

1. The water softener system could be short-brining itself due to the salt “mushing” at the bottom of the brine tank. This situation can occur when the salt breaks down into a fine slurry at the bottom of the brine tank.

Or, when the control valve goes into the brine draw cycle, it can draw the brine from the brine well faster than it can flow into this area. The air check shuts off before all the brine solution has been drawn out. Unfortunately, the brine tank will have to be cleaned out.

2. The brine refill system on the control valve is not allowing enough water back into the brine tank. There are generally flow controls on the brine refill mechanism and they can range from 0.25 to .05 gpm. If they become fouled due to debris, the refill rate will be restricted, a smaller amount of brine will be made and your softening capacity will be reduced.

3. The addition of an RO drinking water system will consume some of the system's capacity. The low flow rates of an RO system generally are not picked up by demand meter systems. You will have to adjust the meter settings or days of regeneration for time clock units.

4. Leaking faucets or the float shut-off valve in a toilet tank will also reduce a systems softening capacity. A pint-per-minute leak down the toilet overflow will not be seen or heard; generally it will not be picked up by a demand meter system, but results in 180 gallons per day additional usage. It's like adding two additional people to a family.

5. Salt bridging in a brine tank can slowly reduce a systems capacity. A brine tank creates a very humid condition and the salt will absorb the moisture. A damp basement or humid summer weather will add to this condition. If a unit does not regenerate often, or when the home heating system starts being used, it can dry out the salt. The salt can turn rock hard, stick to the side of the brine tank (as one large mass) and it will not drop into the water below. There will be no saturated brine available, resulting in hard water. Unfortunately again, digging the hard salt out is the only solution.

6. The family could be just heavier-than-normal water users. Most water treatment dealers estimate usage of 75 to 100 gallons per day per person when setting up equipment that requires a calculated reserve setting. However, some families use 150 to 200 gallons per day per person. This will require talking to the homeowner about their general past and current water usage. They may have two or three teenagers who stay in the shower until all the hot water is gone.

As mentioned earlier, checking the salt and water level in a brine tank can guide you in solving a system's problem. Dealers often ask, “How high should the water level be in a brine tank?” You have brine tank systems set up with grids and without grids. Each has its own calculation.

There is some confusion as to how much salt is dissolved per gallon of water. A gallon of water will dissolve approximately 3 pounds of salt. A gallon of saturated brine will contain approximately 2.6 pounds of salt — what's the difference? If you take 1 gallon of water (room temperature) and add 3 pounds of salt and stir it until all the salt is in solution, you will now have more than 1 gallon of liquid. Take 1 gallon of this solution and it will contain approximately 2.6 pounds of salt.

In brine tanks with no grid, use the following examples to help make your calculations. For example, in an 18-inch-diameter brine tank, each inch of liquid is approximately 1 gallon. When you add enough salt to just cover the liquid, you will increase the liquid height by three times. A unit with a 9-pound salt setting will put 3 gallons of water back into the brine tank (3 inches) after a regeneration. The brine level will be approximately 9 inches when salt is added.

In another example using a 24-inch-diameter brine tank, each inch is approximately 2 gallons. Using a 60-pound salt setting, this system will require 20 gallons of water, which will be approximately 10 inches in height in the 24-inch-diameter tank. Add salt and the brine level will be approximately 30 inches.

These heights will vary due to how far the brine pickup system is raised off the bottom; the type of salt being used; and the distance from the bottom of the brine pickup assembly to where the air check shuts off brine draw.

In brine tanks with grids, the brine tank refill water level has to be above the top of the grid to make up brine (minimum of 1 inch-2 inch). The grid height plus the water level above the grid times three will give the approximate total brine height.

Applying this to the above example for an 18-inch-diameter tank having a 5-inch grid assembly and a 9-pound salt setting, the refill water would never reach the grid platform. The 3 inches of refill water (9 pounds of salt) would be 2 inches short of touching the grid. The brine pickup assembly is raised off the bottom 2.5 inches to 3 inches to compensate for this.

In the second example with the 24-inch-diameter brine tank, determine the height a grid should be for a 60-pound salt setting. The 60 pounds of salt requires 20 gallons of water, which has a height of 10 inches (2 gallons per inch) in the 24-inch tank. If you want 2 inches of water above the grid, the grid legs should be cut at 8 inches. The approximate total height of brine level would then be 8 inches (below the grid) + 2 inches (above the grid) X 3 = 14 inches. You have dropped the brine level by one-half for the same salt setting.

The above information can vary somewhat for different types of systems and water conditions, but will help guide you to other problem areas that go beyond the normal service items.

Mike Hamberger heads the sales and promotion team for the Sanitizer Series product line at Water-Right Inc. in Appleton, WI.