Rear Heating

[Matthew Barber]

Hi All,

Anyone got any tips on using the rear heating controls. No matter what I select all that blows out is cold air. Manual seems confusing on this leading me to believe that you have to have the air re circulation mode on..I select REAR and choose full heat but after 15mins or so of driving despite hot air in the cabin, cold air is blowing from the back..

Matt

 

[Hotel California]

You need to give away if it is the standard or the 3-way you got

 

[B J G]

Did you set the rear to Auto?

 

[Matthew Barber]

It’s the standard setup in the rear is a temp dial and a fan setting. In the front there is a REAR button which activates those controls

 

[WelshGas]

It’s the standard setup in the rear is a temp dial and a fan setting. In the front there is a REAR button which activates those controls

Like this?

 

[WelshGas]

Check the Actuator rods are connected and working.

in the rear of the van, remove the plastic vent panel just behind the driver's side wheel arch, just pull it off with a little care.
On the rear heater unit behind, you'll see a white plastic actuator arm oriented north/south. Servo at its top, coolant flow control valve at its bottom. The servo rotates clockwise as you alter the temperature control which lifts (cold) or anti-clockwise, lowers (hot) the flow control valve at the bottom via the white plastic arm. It's sprung to be in the upper or cold position if you remove/unclip the actuator arm from the servo (at its top).

So unclip it from the top/servo and agitate the [lower] valve by moving the plastic arm up and down, that maybe all it needs. Alter the temp control while its unclipped and see if the servo rotates freely without the plastic arm attached to it.
If the servo doesn't rotate then it's either a power issue or the unit is defective - I don't think these [servos] are very reliable. Don't think you can replace just the servo. The servo might move a little and then return, not sure what that means.

If the agitation worked for you then i would not have the temp control set at fully hot or cold and from time to time, go through this process again to keep the valve moving freely

 

[AlanC]

On the 2010 Cali the actuator servo can become faulty and turn completely through 180º and jam up. This will stop any hot water passing to the rear heater unit.

It is possible to replace just the servo and is a relatively easy job. Unfortunately there are two versions listed on the VW parts list and you will need to make sure the parts tech orders the right one from Germany.

The one that fitted my 2010 van was:
W7E0 907 512

There is a version with an 'A' suffix on the part number which I think is for younger Calis and didn't fit my van.

B.T.W. when you get it fixed, the hot water takes quite a long time to get to the rear heater unit.

Alan

 

[Matthew Barber]

Yes like that but without the buttons underneath. That is for the info will try that out.

I take it the warm air should only take a few moments to come through

 

[AlanC]

Snip.

I take it the warm air should only take a few moments to come through

No, it take quite a long time for the air blown by the fan to get warm.

The driver gets a chilly draft around the legs for about 3-5 mins before the water circulated to the rear heater matrix gets hot enough to warm the blown air.

Not very useful on short runs.

Alan

 

[WelshGas]

Ok

Yes like that but without the buttons underneath. That is for the info will try that out.

I take it the warm air should only take a few moments to come through

, so you don’t have the 3 Zone Climatronic System.

The rear Heater system just provides Heated air or Ambient Air, not chilled air as the Climatronic System does.

It can take 10-15 minutes before you get warm air at the rear as the priority is Engine - Cab Heater - Rear Heater.