2002 Volvo S60T Heater stops working

When I turn the car on I have heat for about 12 minutes, then it starts blowing cool/cold air. The AC is off. The only way I get heat is if I turn the temp control to the red zone. After I get too hot & turn to even 80 degrees, it starts blowing cold air again.

The dealer reset the heater computer & that did nothing. They are saying I need a new heater. Help! This is my 5th Volvo & we run them to at least 250,000 miles & have never had to replace a heater.

I live in Knoxville, so it is not like I have to run the heater nonstop.

Thank you!

I am not totally convinced it it the heater’s computer control, but it could be. Those fancy controls have a habit of going crazy. I suspect they will bet more reliable in time, but I would avoid them if I could.

You might have the car’s cooling system checked (look for air in the system) as well as the vacuum system.

Thanks for your reply! Does it make a difference that everything works fine if the outside temp is 65 or above? 55 & below I difinitely have the problem. The inside temp stays at 69 when it is 44 or 55 outside. I have all outside vents turned off.

If your system uses an infrared sensor to detect the air temp there may be a problem with it. I am not familiar with your system so I don’t know for sure.

Thanks! It turns out that inside ambient sensor needed to be replaced. I now have heat!