Heater Blowing Cold :(

[tommy1340millar]

2005 mk2 1.8 tdci estate.

Started on Sunday, moved heater controls to hot. Worked for about 20 secs, then started blowing cold air.

I searched for similar problems on internet. Removed stereo, no kink in temp. cable.

Where is/are sensors? I do hope it's not the water pump (Car has been a wee bit noisy last couple of weeks)

[IINexusII]

coolant topped up?

[jeebowhite]

it could be either the heater matrix, or the resistor.

Does it do this on all four heater settings?

[tommy1340millar]

coolant topped up?

Yep all ok there

it could be either the heater matrix, or the resistor.

Does it do this on all four heater settings?

Yeah, the fan's ok, it just blows cold air regardless of fan speed or position of the temp. knob (I can hear the tone changing, so the temp flap is moving

[artscot79]

sounds like it may be the water pump with the engine hot can you see coolant flowing into the expansion tank and are all the hoses hot

[jeebowhite]

I would also consider the heater resistor..