2006 XC70 no heat

[JimG63]

Good morning,

The frigid weather here in the northeast is not helping, but my heater isn't working. The temperature gauge on the dash is centered (12 o'clock) once the car warms up, antifreeze level is spec, the heater hoses going into the firewall are HOT. So I don't THINK it's the thermostat. If I have the fan off for a short time and turn it on, I will get a blast of hot air before it quickly cools, so there is at least SOME flow thru the heater. The car has dual heat controls, so I'm wondering if there is any valving that might be bad, or clogged heater core? Or should the temperature gauge be more towards 1 o'clock and I just don't have hot enough antifreeze going to the heater?

Thanks in advance

Jim

[Vovo_merz]

the gauge should be at 12 o'clock so you are good there, I had a similar problem but heat didn't work only on one side so I had my body that works for a volvo to calibrate the heat controls and it worked fine after

[jimmy57]

Turn it on full heat with warmed up engine and then feel both hoses on firewall that lead to heater core.
If both are hot then there is an issue with the system inside. There is no water control valve on that car. The coolant flows through heater at normal flow 100% of the time.
You could have a plugged up heater core if one hose is hot and the other is cool.
If heater core flow seems ok (both hoses hot) then the temp control doors are both stuck. There are two doors each with its own motor and they are on two different control circuits. It would be very unusual for both doors to be stuck at the same time.
The fan off-hot-then cools is symptoms of blocked heater core but you'd have one hot and one cool hose.