A heater control valve is simply a water valve which allows more or less water to circulate through the heater core, depending on how much the valve is opened.he coolant flows  through the heater core all the time.    Temperature is controlled by:    Temperature blend door-control how much air travels through  the heater core -   A small motor that controls the blend door-a rather common  failure point.
In 2002, Tyson fought for the world heavyweight title at the age of 35, losing by knockout to Lennox Lewis. Tyson retired from professional boxing in 2006, after being knocked out in consecutive matches against Danny Williams and Kevin McBride.
Ali is the first heavyweight champion in the history of boxing to lose his title to a novice (who had only seven professional fights). This occurred when Ali lost to Leon Spinks on February 15, 1978. He first decided to take boxing lessons when neighborhood bullies stole his bike and he wanted to get back at them.