So, after 3.5 years my T-CELL-15 appears to be dead. Salt levels are fine (3600ppm), however the panel is reading 2100 ppm, and generating very little chlorine. I've acid washed it on the appropriate stand a few times, same issue. I've been looking for a replacement, and of course checked the smiley face store and they have a W3T-CELL-15 for sale. Is this the same as the T-CELL-15 that came with my unit in 2016?