Hevac faulty when frosty

When the temperature drops to 3oc (when frost alert flashes) the handbook symbol pops up.
Any ideas. I already have a new hevac unit ambient air sensor and a new heater matrix.

Paul

Could be the distribution flap sticking in the heater box,when you start up from cold the flaps to the limit of travel in each direction.If the Hevac Ecu does not see full movement on all three blend motors it flags a fault.
The distribution flaps seem to be tight in the box,when they warm up a bit they free off enough to work.Can be a bit of a bu--er to sort out.
You really need to stick it on testbook to find out exactly what is going on.Hevac on LP RR's is the fussiest system on the car and can be a real pain to sort out,but at least the fault codes usually relate fairly closely to whats going on.(Unlike EAS)

Plugged into test book.
One of the blend motors have stalled and a sensor next to the heater matrix.
LR want 170 plus 8 hours @ 57 +vat
I think i will be giving it a go my self

Thats about right for a dealer on this job,the heater matrix sensor is clipped onto the inlet pipe,that is the easy bit.
Which blend motor stalled ? post back and I'll tell you how to sort it possibly without fitting a new blendmotor pack.

Not sure they didnt tell me so I supose I will have to take dash out and investigate for myself.

Sounds like a long weekend job