Our Softener (Culligan Outdoor Medalist Plus SE Water Softener Series 30/45 Model SoftMinder & Timeclock SN: V05134958 Part #01016486) is displaying an E2 error code on the circuit board screen, and is running water into the drain as though the Regen cycle hasn't completed. How do I reset the control unit ... unplugging for five minutes didn't work. Does the unit need a new seal pac?

It sounds like there is not enough flow through the softener. It must be partially blocking the flow. Flushing the toilet will allow the pressure on the output side of the blockage to drop while the pressure on the input side of the blockage would remain the same. Once the toilet refills the pressure would gradually increase back to 50psi.

Call Culligan on this problem.

Here is a link for the Medallist manual to re-program your unit.
http://www.isingsculligan.com/wp-content/uploads/2013/02/MedallistRevA01016385.pdf
RJH2O

What do you mean by salt is not going through?

This is a Medallist series water softener. Her is the link to Culligan for your owners manual.
http://www.culliganwater.com/residential/resources/timers_manuals.php
For future reference it is more helpful to provide the Model and the year it was installed.
RJ

Hold the REGEN button down for 5 seconds. This initiates a manual regeneration. You can step the unit through the cycles by pressing the UP arrow.
RJ

Check the salt tank too see if it is overflowing. There could also be a crack in the bottom of the brine tank causing it to leak. You need to determine where the leak is coming from. Many times water is leaking from the valve, running down the tank and collecting under/around the salt tank. As far as not cycling make sure the meter cable is plugged in, power to unit, etc. The valve may not be switching tanks, there can be many causes for this. Bottom line is By-Pass the softener until a service tech can come out. These Culligan twin tank systems (9000,9100,8500, Twin-Flo) are actually fleck valves so any water treatment dealer that sells/services Fleck valves can repair this system.
RJ

Its a most common problem with culligan seal pacs. If your softener is under 5 years old you have the worst softener on the market. Culligan was bought out about 5 years ago by a canada group. they changed every thing and nothing is made in the usa any more. You will have to buy a new one from culligan and pay over 90.00 for it. The old seal pacs lasted 15 years or more now your lucky if you get 2 years.

I have the same problem... did you find out what was wrong???