When I got mine, the flow through the head was reverse of what it should be. The flow was entering the outlet and dumping out at the top and draining down through the media and entering the inlet spout and flowing through using that path. In a deionizer, water is supposed to flown down the inlet spout toward the bottom of the tank then flow up through the media, this is how channeling is prevented. I had to switch the brass fittings on the head around. Make sure to check yours because if mine was wrong, yours probably is too
Kenneth Darke 
austin boyles 
