It's fairly easy to remive the valve and open the resin tank. If your not certain as to how to do this, I can try to explain it.
First put the softener in bypass.
Press and hold the select button to manually start a regeneration. (This is to relieve the pressure in the softener).
After this, press the regen button three or four times to bring the valve back to the "service" mode.
Now the hard part. Pull the clips out where the water lines connect to the plastic bypass. With the clips out, you can now scoot the softener away from the supply piping. (This is to disconnect the softener piping from the house piping.)
On the left side of the valve (when your facing the front of the unit) there is the venturi assembly. There is a clip holding the venturi on, pull up on this clip and then pull off the venturi assembly. May have to wiggle it a little.
Around the base of the valve, where it joins the resin tank, there is a safety clamp. Simply unhook one of the clamp buckles, and remove the clamp.
Now the valve can be removed by simply pulling up and off. The top distributor should be attached to the valve and come off with it, if not, pull it off the distributor pipe.
You can now look into the resin tank and see what the resin looks like. This whole process takes about 5 minutes or so.
Most of the professionals here regard the Ecowater systems (this is who made your Whirlpool system) to be cheap and throw away. But if the only thing wrong with the unit is failed resin, it can be replaced and for a $150 and you could get another 7-15 years out of it. (Chlorine also degrages the O-rings in the valve, but they can be replaced for around $40 in about 15 mimutes time.)
You can use a shop vac and vacuum out the old resin. Then pour in the proper amount of new resin (the type and amount is listed on the information label). (No gravel is used in this small tanks.) After this fill the tank with water and push the distributor back into the tank (the water will allow the beads to move around and the distributor will push in easily). Then just put the valve back on, fasten the clamp, reattach the venturi, wiggle the unit back into the supply piping, slip in the clamps, plug the transformer back in and put the bypass back into service.
A cubic food of high capacity resin runs somewhere around $125, maybe a little more, and that's a lot cheaper than buying a new system. They also make better resin that able to resist city water better. (There are experts here that can advise what would be best).
City water has chlorine in it, which destroys resin. I've read that resin should last 20 years (degrades around 5% per year), and half that when exposed to chlorine. Your softener was continuously exposed to chlorine without being regenerated and this probably accelerated its degeration.
If your resin has failed and you don't want to replace, you have the option of replacing with a better unit or simular unit. A better unit will run around $600 if you buy online, (you will have do your own installation), twice that if you buy local. If money is a concern, you could replace with a simular unit (plumbing should fit exactly) with a unit I seen at Sam's Club for $370. I would imagine Cosco has a simular unit and price. Sears units are also a good buy when they are on sale - which is all the time.
Chlorine is still going to be a factor with any softener you buy and a pre-filter that takes out the chlorine before it gets into the softener should be considered. (There are several professionals here that can advise you on this.)
If you decide to purchase local, they will provide everything for your water conditions. It will be the most expensive route to follow, but no worries. I would avoid Culligan or Sears and go with a professional service, look in your yellow pages and ask around. Rough guess, prices would start around $1000 and run to $2000 depending on what they sell and your needs.
