heater runs cool - Page 2

jamiecoysh · 08-02-16, 05:07 PM

The foam backing has broken down on the centre flap allowing cold hot air to mix

jimh · 08-02-16, 09:45 PM

It's an Ur quattro. There are no flaps which control air temp.

The centre vents blow cold air only. The windscreen, side & footwell vents blow warm or cold air. The temperature of the air to those vents is controlled by regulating the flow of coolant through the heater matrix by the heater valve under the bonnet (controlled by the hot/cold slider on the dash).

Downside of that design (and probably why it was changed to air flaps on later models), is that it takes a while for the air to cool after changing the lever from hot to cold (residual heat in the matrix).

08-02-16, 05:07 PM	#11
jamiecoysh Grown up member Join Date: May 2013 Location: Torquay, Devon Posts: 119	The foam backing has broken down on the centre flap allowing cold hot air to mix

08-02-16, 09:45 PM	#12
jimh Grown up member Classic Audi Club Member Join Date: Dec 2008 Posts: 122	It's an Ur quattro. There are no flaps which control air temp. The centre vents blow cold air only. The windscreen, side & footwell vents blow warm or cold air. The temperature of the air to those vents is controlled by regulating the flow of coolant through the heater matrix by the heater valve under the bonnet (controlled by the hot/cold slider on the dash). Downside of that design (and probably why it was changed to air flaps on later models), is that it takes a while for the air to cool after changing the lever from hot to cold (residual heat in the matrix).