Hello!
When I set temp knob to manual and call for max cool with mode knob off, my heater valve doesn't close so the heat, thought little, pass in the cabin from the closed flaps of the heater matrix box!
The valve closes only if I set mode knob on low, norm or hight...
Is this normal?
I'd like to close heater valve without holdig blower fans on!
Please keep in mind that my A/C doesn't work because gas circuit is completely empty... Maybe is this the problem?
Thanks for the help!
Tommaso

 

If he RH switch is set to off 9ie you have truned the aircon system off), the water valve will be open. The water valve only closes at max cool when the system is running. In other words the default mode for the water valve is open.

 

This is correct and a real PITA when you want to drive on a nice sunny day with AC off and windows down.

The other thing is when on defrost you get full heat, really good when you need to defrost on a 30°C day.

 

Why not go to the motor side of firewall cut the hose feeding the heater install an off-on valve.

 

Easy.

Vacuum applied will close the valve.... so just run a vacuum hose from a convenient vacuum nipple on the engine to the heater valve.

Cheers
DD

 

I bought a hot water shutoff solenoid valve 12volt to install it will turn on when AC is switched on, haven't installed it yet I'm waiting till engine is out.

 

Got a link to that please Warren?

 

This is not the exact same as mine but close

As long as the valve is normally closed and rated at 100°C it should work.

https://www.ebay.com/itm/US-Stock-12...-/401200900899

 

I'm curious about this.

The Delanair system closes the heater valve when max cooling is called for.... and opens it in heating and blend modes.

It this function inoperative on your car or do you have a different rationale in mind?

Cheers
DD

 

 

The valve is only to shut off the hot water when the system is turned off. I drive a lot with the AC off and windows down and warm air comes out of the vents as well as the front of the console gets warm. I have cable tied off the heater tap a couple of times and this fixes the problem.

The valve will also allow me to manually turn the heat off when I need defrost on a hot day so I don't get baked.

If I run the AC it's not a problem.