5 Common Softener Issues
It sometimes feels like water softeners have been around since the dawn of time. That feeling isn’t entirely wrong: here’s a history of ion exchange for those of you who are interested. Today, ion exchange and softeners, in particular, are used everywhere from cottages to the largest industrial applications. Whether you’ve got a little home softener, a mid-sized commercial system or a large industrial system with several hundred cubic feet of resin, the common issues discussed in this post could well be affecting your system.
Flow vs size mismatch
Ion exchange resin, found in softeners, scales up or down extremely well. You can build a very small or very large system using the same basic principles. One very key principle is that flow rates must match the system size.
We’ll leave detailed softener design for another post, but here are flow-related issues that crop up regularly:
- Insufficient service flow causing channeling – only part of the resin gets used.
- Too much service flow causing kinetic leakage – higher than normal hardness leakage.
- Insufficient flow during brine draw / slow rinse – lower capacity and higher leakage.
You want to make sure your softener is operating within its designed flow range. Any significant peaks and valleys will result in sub-par water quality or softener capacity.
Wrong Salt Dosage for Desired Leakage
Softener resin is known to leak a certain amount of hardness based on a variety of conditions including inlet water quality, flow rates, temperature and quantity of salt used during the regeneration. If all design flow rates are respected the biggest factor affecting in-service hardness leakage is the amount of salt used per regeneration.
Engineering guides for softener resin should provide expected leakage levels. Ask your water treatment professional about the expected hardness leakage for your system for different quantities of salt used in regeneration. You may be able to save on salt if you can accept some leakage or you may find that you should increase your salt dosage (or change to Purolite SST60 resin) to lower leakage.
Incorrect Regeneration Cycle Timing
Regenerating a softener is simple: expose every resin bead to 30% saturated brine for 30 minutes. This is not the same as having a 30 minute brine draw/slow rinse step. The way to tell how long your resin is in contact with brine is by measuring salinity (or conductivity) at the drain every few minutes during the brine draw, slow rinse and fast rinse cycles. The graph of these measurements over time produces a “brine curve” which tells a whole story about the health of your softener’s regeneration program.
In short, it should rise and fall sharply and achieve a plateau at 30% saturation for 30 minutes. Once that’s nailed down you can start playing with longer or shorter exposure times to optimize your system.
Horrible Brine Suction
Ok, let’s face it. That 30% saturation plateau is a great goal but lots of systems just aren’t achieving it. This can be due to two major factors:
- Incorrect injector selection (or pump selection if brine is pumped)
- Installation issues
Injector or pump selection is easy enough: you want to select the right equipment to give a ratio of 2 parts water to 1 part saturated brine at brine draw flow rates and operating pressures.
Installation issues include but are not limited to the following:
- Overly long brine lines (loss of suction occurs)
- Restrictions at the drain including physical obstructions, drain lines rising a number of feet before falling, etc.
- Air leaks in the brine line and fittings
- Clogged brine valve
- Control head malfunctions
While most small softeners barely have any distribution systems at all, they can sometimes cause issues. Uneven distribution of water or water bypassing the resin bed via a leak in the distribution system are not uncommon.
If you know that your flow rates are good and that your regeneration cycle is on point (you did a brine curve, right?) you may want to start looking into your softener’s distribution hardware. Is there any reason why water would pass more easily in one area or another? If your system has a riser, is it the right height and is it sealing well with the control head?
We’ve also seen systems built with inadequate top distribution that caused resin turbulence. Really, it looked like a resin-filled washing machine when you looked inside the tank. Luckily this client could see inside his tanks. It would have been very difficult to spot that problem otherwise.
I really hope this article will be useful to those of you who have been bashing your head against the wall trying to figure out what’s wrong with your softener system. The list of issues presented above is not exhaustive by any stretch of the imagination. Softeners come in a variety of configurations and it isn’t always easy to figure out what’s going wrong.
If you’ve got an issue you’d like some help with just drop us a line or leave a comment below.