Heat only works on max temp selection

[MW3Designs]

Just purchased my first Volvo, 2006 XC90, and noticed I am only getting heat when I turn the selector all the way to red. If I turn it down one click I get cold air. Didn't notice this when I picked it up, as the main concern was AC as it was hot out. Getting colder here in NY, hopefully someone is familiar with this issue.

 

[XCMike]

Possibly you have a bad heater control valve, what that does is control the heat going into the car.
https://www.fcpeuro.com/products/vo...e-s60-v70-xc70-s80-xc90-genuine-volvo-9171550

 

[MW3Designs]

Possibly you have a bad heater control valve, what that does is control the heat going into the car.
https://www.fcpeuro.com/products/vo...e-s60-v70-xc70-s80-xc90-genuine-volvo-9171550

Where is this part located on the vehicle, difficult to replace?

 

[stl_jh]

I have this same problem on my brand new 2021 XC90. Going to the dealer for a third time.

 

[Vince Rovito]

I had a similar problem that culminated in a heater motor failure. Researching the issue it appears that the resister in the unit controls the speed. Mine stopped completely and when I removed it from the vehicle (almost lost my religion on that) the motor was fine but resister is toast. Replaced the resister and the reinstalled the unit and it works fine at all speeds. Good Luck.

 

[Vince Rovito]

These are some of my notes:
Here are some common signs that your vehicle’s blower motor resistor is bad:

Loss of HVAC fan control (total or certain speeds)
The fan only works on its highest speed setting
No air coming from vents
Intermittent or inconsistent fan speed

Do the resister first. It is actually unusual for the motor to fail. Generally when it starts to fail it makes noise as the dry end bearings get hot.