Heater issue.

[baconJazz]

Several times over the last few weeks the fan heater has been blowing cold air in to the cabin even whilst the engine is operating at the correct temperature , and then as if by magic hot air suddenly kicks in. It's also happened where Iv'e got back into the car after a journey where it's been working fine , and with the engine still warm , it blows cold again.
Is this a sign of something expensive to come ! ?

 

[mr nurburgring]

Mine does this occasionally, never looked into it as it’s so infrequent. If I turn the heater off and back on it sometimes cures it. A glitch maybe.

 

[colb]

Usual cause is an air lock in the system, get the front of the car as high as you can, drive on ramps would be ideal then open the radiator bleed screw and run the engine up to temp. Watch for air comming out of the bleed screw,as soon as no more air comes out screw the bleed screw back in.

 

[ph001]

It’s not an airlock, it’s the hvac control panel getting it’s knickers in a twist. If you rotate the temperature dial fully anticlockwise and clockwise it usually sorts itself out. They tend to play up when the battery volts are low, so maybe consider checking battery volts.

 

[baconJazz]

It’s not an airlock, it’s the hvac control panel getting it’s knickers in a twist. If you rotate the temperature dial fully anticlockwise and clockwise it usually sorts itself out. They tend to play up when the battery volts are low, so maybe consider checking battery volts.

Brilliant , cheers !

 

[ph001]

....by the way, if that doesn’t work and your battery volts are good it could point to the infamous electric water pump. If the coolant isn’t being pumped then no hot water going around the heater matrix.