Thread: Extremely hot heater matrix. Hot in cabin.

my 2c, is that the ventilation system is not closing off the heater air flow port , the heater matrix is actively hot at all times as part of the quick warm up cycle thru the thermo-stat, its the primary coolant circit,radiator for the motor, with the main radiator at the front of the car as the back up,
have you tried cycling manually thru the ventilation output settings, instead of leaving it on auto air, that may free it up, and yes the aircond will never beat the heater matrix at full ever,

FYI

Heater matrix

The heater matrix is fitted in the heater assembly inside the passenger compartment. Two pipes pass through the
bulkhead into the engine compartment and provide coolant flow to and from the matrix. The pipes from the bulkhead
are connected to the matrix, sealed with 'O' rings and clamped with circular rings.
The matrix is constructed from aluminium with two end tanks interconnected with tubes. Aluminium fins are located
between the tubes and conduct heat from the hot coolant flowing through the tubes. Air from the heater assembly is
warmed as it passes through the matrix fins. The warm air is then distributed in to the passenger compartment as
required.

+

HEATING AND VENTILATION, DESCRIPTION AND OPERATION, Description.

When the engine is running, coolant from the engine is constantly circulated through the heater matrix.

HEATING AND VENTILATION

80-6

DESCRIPTION AND OPERATION

Control flaps

Control flaps are installed in the heater assembly to control the temperature and distribution of air. Blend flaps control
the temperature and distribution flaps control the distribution.

Temperature and distribution control

Figure shows flaps set for medium heat to face level and footwell outlets

1

Windscreen/Side windows outlet

2

Heater assembly casing

3

Air inlet

4

Heater matrix

5

Front footwells outlet

6

Rear footwells outlet

7

Face level outlet

Blend flaps:

Two sets of three blend flaps, one LH and one RH, regulate the flow of air through the heater matrix and
a heater matrix bypass, to control the temperature of the air leaving the heater assembly. The two sets of blend flaps
operate independently to allow different temperatures to be set for the LH and RH outlets.
Each blend flap is attached to a spindle. The end of each spindle extends through the side of the heater casing and
is attached to a common lever mechanism on the related side of the casing. A control cable is installed between the
lever mechanism and the related temperature knob on the control panel. When the flow is split between the bypass
and the heater matrix, the two flows mix downstream of the heater matrix to produce an even air temperature at the
individual outlets.

Distribution flaps:

Separate distribution flaps are installed to control the flow of air to the footwells, windscreen/side
windows and the LH and RH face level outlets. The distribution flaps are attached to spindles that extend through the
RH side of the heater casing and are attached to a common lever mechanism. A control cable is installed between

the lever mechanism and the distribution knob on the control panel.

Must be problem mate. My D2 is never hot on the floor vents unless heater is on. My D1 gets warm around the trans tunnel but I have always put that down to the auto and different design whereas my D2 manual is cool.

Cheers

Thanks for everyone's input. I appreciate you all discussing it with me.

Had I not had a D2 whose aircon was excellent previously, I'd accept the "that's just how it works" angle some of you have suggested.

I've done some googling and come up with another possibility. It seems some people have had the issue when there's an air-lock in the heater matrix. Eg after a poor bleeding when it has been disconnected (and I know this one has been).

I gave it a half arsed bleed last night and it seemed to improve, but the ambient temp outside was way down also. I might disconnect the heater matrix and flush it and see what happens.

Anyone got a suggestion for removing a rubber hose that wont budge?

Wil