[Razorback1980]

I have seen two different heater designs on other cars but have never taken the 944 heater apart. I have seen where the control valve regulates the amount of water that runs through the heater core and the second design is the valve just turns the water on or off and there is an air flap in the control unit that mixes the hot air after it has passed through the heater core with fresh air from outside to regulate the temperature. I thought the 944 regulated water, but apparently it regulates air instead. I guess your hard work has taught me something today. Appreciate that and Good Work on your part. Never a reason to argue with success is there? Hope your drive was fun!