I have a strange problem with the parking heater on my 2010 VSE. The FBH was replaced under warranty a year or so ago and fires up with no problem at all. When it works, the windscreen and front floor vents produce warm air, however the rear centre vents pump out cold air so the cabin doesn't really warm up at all.

Tried changing temperature dials - no difference.

No faults found by my IID tool.

Rear vents do put out warm air when engine running as expected.

Anyone had this before or any ideas what it might be?

Thanks
Tim

Sounds like you have a normal running FBH to me if you have an AGM battery
Am not sure post timing cycle changes the FBH on the my 10-12 heats the back anymore.
Don't think mine ever has when the time was reduced from 30 to 17 minutes

Thanks for the reply - yes mine does have the AGM battery with the reduced running time. I was surprised it was putting any air out of the rear vents as well. Everything I have read suggests it should only be the front vents. Makes me think one of the flaps is stuck open or something like that which is forcing air to the rear when it shouldn’t be.

As the colder weather has been here a while I am still trying to find out if I have a fault or not with the rear passenger face vents with the parking heating ...is there anybody that could quickly test for me? Can you stick your hand in front of the rear passenger vents when the parking heater is running to see if hey have any air coming out of them and if so is it hot or cold!

Any help would be appreciated - it is going into LR next week but want to be armed with the fault if I can!

Thanks

Tim

Just checked in mine.
Cold air from rear vents...warm from front vents at the side and under windscreen.

Mine just runs on auto.
Nothing comes out of the face vents....it is not possible in my RR to adjust away from auto once FBH cycle has started.
Maybe for those that get warm air out of the face vents the car remembers the last setting on shut down and pushes warm air out the front.
I will try later on.

Sounds like your FBH is very normal and ordinary.
Don’t expect anything spectacular from it. In 17 minutes it will defrost the windscreen and windows and put a little warmth into the cabin.
For those that say the cabin is very toasty....that was my experience on a 30 minute FBH cycle too.

Was going to add...

When the software downgrade was done to convert from 30 to 17 minutes there were other changes too
For example the heating for the mirror de-icing was turned off ...
Could be very possible that with the original 30 minute cycle hot air also came out the rear
But maybe they changed this too to ensure at least the windscreen and windows were cleared.

Thanks for that, very much appreciated - seems like the software “upgrade� has changed things and that perhaps mine is operating normally. As you say perhaps wishful thinking on a toasty warm cabin! Incidentally last week it was -2 and even after a 40 min drive my washer jets were still not working, now wondering if that has anything to do with the mirror heating you mentioned below.

I would use a better screen wash then !

Fair point!