Monogram side by side ice maker fill tube appears to be freezing. Line from water valve to fill tube is blocked until I defrost it. Once defrosted it makes a couple of batches of ice and then freezes again. Water valve is operating and delivering the correct amount of water and does NOT appear to be leaking between cycles. I replaced the fill tube heater but it did not correct problem. New heater and old measured same resistance so I was not surprised that it did not correct problem.

When does fill tube heater activate? I can check to see if it is getting power if I know when it activates during the cycle.

Any other suggestions for overcoming/correcting this problem?