Heater valve X 2

[nissanh]

Now my car has much better AC!

During the summer I killed the heater core in my car. I bypassed the heater and immediately noticed the AC is now vastly improved. (I did a thread on this subject).

After installing a new heater core I used a ball valve to close the hot water flow to the heater during the summer, and many at t4r did not liked it. So I figured to use another valve to the return hose and connect it to the original valve through a cable. When I open the heater valve, it will also open the valve on the out put line, and will close when I close it. This method will totally close the hot water flow into the HVAC system when you chose AC mode, which leads to improve the AC.

 

[audiness]

so you have 2 heater valves now, one on the input and one on the return line? I am surprised that it improved your A/C because if the valve is shut, it should not be sending hot water into the heater core

 

[nissanh]

Well, these valve are plastic to plastic contact. So no perfect sealing. With the pressure inside the engine, it will send hot water quite a bit. I noticed a hot air flow when I select outside fresh air, selector towards the cold and AC off! Also when I pulled the heater control unit I saw the door is not completely isolating the heater core. So this triggers me the connection between the hot water in the cooler and why I get hot air when I select cold air from out side.