Heater blows either hot or cold

[Lefty1991]

Does anyone have any idea why when set to 19 degrees the blower is freezing cold and when set to 21 degrees it is boiling hot, for some reason 20 does nothing and there is not modulation in temp, looking at the heater valve in the trunk between 19 and 21 it travels full stroke

[jon]

I seem to remember the heater does that if the internal temp sensor become disconnected.

[Lefty1991]

I seem to remember the heater does that if the internal temp sensor become disconnected.

Is that the sensor in the dash by your left knee?

[Pauln]

I seem to remember the heater does that if the internal temp sensor become disconnected.

Is that the sensor in the dash by your left knee?

I think that's the sensor used if you have climate control to automatically adjust the heater and aircon settings to maintain the temp you set, so could well be the culprit.

Paul

[CalMac]

Pfft just put the blowers on hot and have the windows down for mad vroom noises