Replacing Heater Matrix Citroen C4 (B7)

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Replacing Heater Matrix Citroen C4 (B7)

Post by GiveMeABreak » 25 Jan 2019, 14:13

At the request of one of the members, here's the official guide on replacing the Heater Matrix on Citroen C4 (B7):


Disconnect the Battery - Following the battery disconnection / connection procedures.

Remove the side Trim from the centre console:Remove the Accelerator Pedal:
Cutac Matrix Flange A.PNG
Cutac Matrix Accel B.PNG
Move the Front Seat Back as far as possible.
Unclip using a trim removal tool:
  • Clip (at "b")
  • The trim (1) (at "a")
Remove the trim (1).
  • Remove the 3 bolts (3).
  • Disconnect the connector ( as "a").
  • Remove the accelerator pedal (4).

Heater Matrix

Depressurise the cooling system. Note: Refer to the separate procedure at the end of this section for this operation!
Cutac Matrix A.PNG
Cutac Matrix B.PNG
  • Position the tools hose clamps on the hoses (5).
  • Press on the locking clips (3) to disconnect the hoses (5).
  • Disconnect the pipes (5).
N.B.: Evacuate as much coolant as possible from the heater matrix using an air gun placed at the inlet
Position a receptacle to recover the coolant.

  • The (4) bolt
  • The retention panel (1)
  • The rubber seal (2)
  • The 2 bolts (10)
  • The fixing panel of the heater matrix pipes (6)
  • The clips (9)
Move aside the heater pipes.

  • The 4 bolts (8)
  • The heater matrix fixing panel (7)

Cutac Matrix C.PNG
  • Move aside the heater pipes (11).
  • Remove the heater matrix (12) (In the direction of the arrow "a").

  • The matrix (12)
  • The heater matrix pipes (11)
  • The heater matrix fixing panel (7)
  • The 4 bolts (8)
  • The clips (9)
  • The fixing panel of the heater matrix pipes (6)
  • The 2 bolts (10)
  • The rubber seal (2)
  • The retention panel (1)
  • The (4) bolt
  • Join the hoses (5).
  • Remove the tools [4153-T] (Hoses (5)).
  • Fill and bleed the cooling system.
  • Check the sealing of the cooling system.
Refit the Accelerator Pedal and Side Trim.

Depressurising The Cooling System (Supplementary Procedure)

207 Cooling Parts D.PNG
207 Cooling Parts D.PNG (39.83 KiB) Viewed 82 times
207 Cooling Parts E.PNG
207 Cooling Parts E.PNG (38.31 KiB) Viewed 82 times
207 Cooling Parts F.PNG
207 Cooling Parts F.PNG (18.76 KiB) Viewed 82 times
207 Cooling Parts G.PNG
207 Cooling Parts G.PNG (45.9 KiB) Viewed 82 times

Draining the Cooling System

Put the vehicle on a hoist.
  • The protective panel under the engine (according to equipment)
  • The de-aeration chamber plug (Carefully)
N.B.: Place a clean tray underneath the engine to recover the coolant.
207 Cooling Hose.PNG
  • Uncouple the pipe (1) (at "a"); Using tool [0165-2] (Flexible Clip Pliers basically).
  • Open the bleed screws located on the coolant outlet housing and the heater pipe.
  • Allow the coolant to run out.
  • Drain the cylinder block (if necessary).
Filling the Cooling System

Connect the hose (1) (at "a") ; Using tool [0165-2] (Flexible Clip Pliers) - and this is where they suggest using new clips!
207 Cooling Parts C.PNG
"A": Fitting with filling cylinder offset ; Using the tools [0173], [0173-B], [0173-C].
"B": Fitting with filling cylinder direct ; Using tool [0173-2].
Fit the filling cylinder, blank and adaptor assembly on the expansion chamber (according to assembly).
Open the rod on the filling cylinder.
Slowly fill the cooling system with clean coolant.
Close the bleed screw when the fluid is flowing freely without any air bubbles.

N.B.: The filling cylinder should be filled to the 1 litre mark for correct bleeding of the heater matrix.

Degassing and Checking the Cooling System
Open the rod on the filling cylinder .
Start the engine.

N.B. : The air conditioning control should not operate during this phase.

All Engines EXCEPT EURO 6
Keep the engine speed at 1500 - 2000 rpm, up to the second cooling cycle (cooling fan(s) cutting in and out).
CAUTION: Check that there are no coolant leaks.
CAUTION : Check that the level of coolant in the filling cylinder is sufficient.

Diesel engine Euro 6 Only
The cutting in of the fan assembly for 10 seconds indicates the switch to after sales degas mode.
Accelerate to an engine speed above 2300 rpm for more than 10 seconds to switch to degas mode.
Maintain the engine speed at 2500 rpm until the fan assembly cuts in again.

Degassing - Continued
CAUTION: Check that the level of coolant in the filling cylinder is sufficient.
Stop the engine.

ESSENTIAL: Do not remove the filling cylinder while the engine is hot.
  • Leave the engine to cool.
  • Blank the filling cylinder using the blocking rod .
  • Remove the filling cylinder , plug and adapter assembly.
  • Check the coolant level when cold.
  • Top up the coolant to the "max" level (Cold).
CAUTION: Do not fill the system past the max mark.

Refit and tighten the cap on the header tank.

CAUTION: Check that the cooling system filler cap is locked (For bayonet cap).

  • The protective panel under the engine (according to equipment)
  • The vehicle to its wheels

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Re: Replacing Heater Matrix Citroen C4 (B7)

Post by furriegurrie » 25 Jan 2019, 14:53

A couple of weeks ago I replaced the heater matrix in my Pluriel. This is a very similar job. One additonal tip besides using the air gun to get as much coolant out of the matrix might be to flush the matrix with water using a garden hose before using the air gun. In this way if there is any residual fluid left when disconnecting the pipes in the cabine it will be clean water instead of coolant...

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Re: Replacing Heater Matrix Citroen C4 (B7)

Post by Cutac » 25 Jan 2019, 18:36

I've just done the job and would like to add a few tips.
Pipe clips(9) are stubborn. Easiest way to take them off is to bend them(expand) and pull them at an angle.
Pipes(11) are likely to be stuck to the matrix so just pull them until they come off. Matrix itself can get stuck several times while being removed or refitted, so just use some force.
Pipe bracket(6) doesn't need to be removed totally, just remove the lower bolt and it will flex enough for pipes to be moved around.
And before removing the pipes, put a big towel under them and stick it under the dash, there's going to be a lot of coolant, no matter how hard you try to get it out before. And start by removing the lower pipe first, and when all the coolant is drained, then remove the upper pipe.
Additionally, leave the matrix exposed(don't fit the trim) after you've finished so you can be sure nothing's leaking into the carpets.

EDIT: I've changed my matrix since the heating wasn't good on the passenger side.
This is what came out of it when I flushed it.

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Re: Replacing Heater Matrix Citroen C4 (B7)

Post by white exec » 25 Jan 2019, 22:35

That heater matrix looks almost stainless steel! :luv: