Resin exchange, is it worth it?

So your water pressure is low and you suspect your water softener.

This is a common problem for water softener owners on city water where chlorine and ammonia are added to the water supply to control bacteria. These chemicals are hard on resin, especially low-grade resin, and will sometimes cause it to break down.

When ion-exchange resin fails, it expands and becomes soft.

As the beads puff up, it reduces the amount of free-board or empty space in the resin tank and the result is low water pressure throughout the house. Many people think this is a city water problem but if you call your municipal water company, you will almost certainly be told that it is your water softener.

The first thing to do is to bypass the softener.

This is easy to do on brand name North American valves as the bypasses will be readily identifiable, usually with 2 red handles. Turn both in a clockwise direction until they close. This will be a quarter turn.

Next, turn your water back on at any faucet to see if the water pressure has returned to normal. It did? Okay, you have confirmed that the resin has failed.

What should you do?

If the softener is older than 10 years, you may want to think about replacing it. If it is a cabinet model, you should definitely replace it. If it is a 2 piece system, less than 10 years old, consider a resin exchange. Keep in mind that this is messy, labour intensive and not always successful.

If you are doing it yourself, you will have to purchase resin, riser and possibly an o’ring kit from a local water softener store or online. You probably will not be able to purchase these items from a hardware store. Expect to spend around $200.

If you pay to have a resin exchange done for you, expect to pay $400 to $500.

A plumber might suggest you replace the entire tank as this is far less work. In some cases, resin exchanges just can’t be done, but it depends on the brand of softener you have. Refilling a resin tank embedded in a cabinet is almost impossible, and probably not worth the expense.

Remember, if you are going to try it yourself, disconnect the softener first and make sure you can unscrew the valve. If it’s seized, then you will save yourself the trouble of buying the resin. 

Disconnect your softener, remove the valve, empty the tank.

Once you've done that, the rest is pretty easy. Inspect the riser for cracks as well as the upper media screen. Rinse out your tank, replace the riser, tape the top so no resin can go down the tube, then pour in your new resin. Try to buy 8 or 10% cross-link, North American made. It's an eye irritant, so wear safety glasses.

Reconnect the water softener and turn it on.

That's about it. Do a manual regeneration to remove air from the tank and to rinse the resin. The most common failure after a resin exchange is that the turbine stops spinning so your softener stops metering and regenerating by itself. This is usually a resin bead that has lodged in the turbine during the procedure. You can take the valve apart and clean it, or put your softener into over-ride by simply choosing how often you want the unit to backwash.

You are done! 

Keep in mind that resin replacements don't always work. On a final note, your old softener is almost certainly not as efficient as a new one, wasting salt and water, so you should compare the costs of new vs repair with that in mind.