GC, I ran into a possibly similar issue a few weeks ago. Please check the volts and amps (open the white control box and start pressing the 'diagnostic' button - I hope you still have tha owners manual, it can tell you the values you are looking for) the presses go like this:
#1 = water temp
#2= volts the cell is using
#3= amps the cell is using
#4= % output (what the dial is set to)
#5= instant salinity (how much salt is in the water currently passing through the cell
# 6 & 7 model and software revision.
NOTE, the cell needs to be generating when you do this, the easiest thing to do is put it on 'superchlorinate' and wait a few minutes. The voltage should be ~ 22.0 - 27.0 (check the manual for the exact #s) and the amps should be 4.8 - 7.9 (I think I got that one right). If your numbers are not in the suggested range call Goldline , be prepared to wait at the first prompt press 2 and wait for a human to talk to you (the other option is to use their on-line tech to try to help you) You want to have the cell's serial # (having the box's # would probalby be a good idea too). If you are calling, use your cell phone or a cordless so you can be at the unit when they start asking ?s (you will need a digital voltmeter to do some of the things they want to know - if you don't have one or can't use it, get someone there who can before making the call) When I went through this a few weeks ago I was told that the transformer and rectifiers were bad, I ordered replacements, replaced them and still had the same problem, however my voltmeter decided that it didn't want to work anymore so I have to call in their 'traveling tech' to see what the real problem is. Just a little experience talking here, trying to save you time and wasted phone calls. Please let me know how it works out and what the fix was (similarly, if I find out what's wrong with our unit, I'll post to let you know)