Bruce

  One thing I should have mentioned in my directions on hooking up a water tank fill adapter is to clamp all the fittings from the drain valve up to the tank. The pressure from the water supply system running through the small 1/4" drain valve puts a strain on the barbed fittings and the tubing could pop off and spray water inside the cabinet.
 I usually only open the water valve part way so as not to put the full force of the supply water pressure on the drain system. As I said it takes about 8 minutes to fill the tank this way.
  There are 2 drain valves under the front of our TM, one small drain for the tank and a larger one for the pump. Be sure to hook up to the valve for the tank and not the one for the pump. I do not know what the consquences of putting 40 or more lbs of water pressure on the drain side of the pump would be!
  It's possible that the rate of flow through the drain valve is determined by the size of the vent rather than the size of the drain valve & tubing in which case having a larger valve & tubing would not speed up the process?

Bruce