I have just replaced my heater control valve (second time, first one leaked!) and I'm still getting much heat. I have left the upper "cubby" out--I tightened the new heater hoses to the coil through that hole-- and that baby gets way too hot to touch, even with the valve closed, all the way to cold. I checked the valve before I installed it and it seemed to be working fine, the little gate slid open and closed and I couldn't blow through it when closed. Has anyone else had this problem? I am thinking of getting a hose clamp and leaving it pinched untill winter.