Not sure if these issues are related, but I wondered if anyone else has experienced them. I'm in a Dec '15 Sport HSE Dynamic 3.0 diesel. Firstly, the heated seats - especially the driver's - seem to be operating on reduced power. I used to have to turn it off after about five minutes because it got so hot, but recently I get no heat at all or just a very slight warming, even if left on for an hour or more. The heated rear window seems to be always on, even when apparently switched off (tell-tale light extinguished); this is apparent when the car steams up inside, which it often does when there are more than two people in the car and it is raining. I've tried various settings for the climate control/air con and the only thing that seems to clear it (eventually) is to have it set to max defrost, which automatically triggers front and rear heated screens (but even without doing that, you can see that the heated rear screen is clearing the condensation, even though it's off!).

Thanks in advance for any suggestions. 14.5MY SDV6 HSE Dynamic Indus silver/lunar/ebony 20" wheels, InControl, full-size spare, electric tow bar, adaptive xenons, adaptive cruise control, auto main beam assist. Gone: TDV8 HSE; Zermatt silver/ebony, 19" off road alloys, active diff, particle filter, tow pack (it was fun) BMW 730D SE (great car, sadly missed). Ford Focus RS mk2, Ultimate green, lux pack 2, bluetooth. The start of my mid-life crisis.
IN THE GARAGE: BMW i8 - the mid-life crisis continues and it's great fun.

The heated rear screen will come on automatically if the car senses "mist" - the telltale light does not illuminate in that case.

As for your difficulties in demisting - no such thing for me, so there must be summat up.

Is there a water leak into the car somewhere leading to soaked carpets and high internal humidity level?

You aren't storing something wet/damp in the car overnight (light swimming gear)?

And is your usage pattern leading to low battery charge, which might be why the heated seats are not as fierce as they usually are (battery management system switches out "unnecessary" loads if charge levels are low)?

Block air intake drains leading to a soaked pollen filter?

Just some ideas for you to check out. MY2016 HSE D SDV6 - gone due to fuel dilution problems.

By the age of 50 you have the face you deserve - George Orwell.

Quote:

The heated rear screen will come on automatically if the car senses "mist" - the telltale light does not illuminate in that case.

Only discovered it at the end of my Jaguar days, have realised it operates the same on the Sport. The "mist sensor" is in the rear view mirror housing, drivers side (on a RHD vehicle) - look for the open slots. MY2016 HSE D SDV6 - gone due to fuel dilution problems.

By the age of 50 you have the face you deserve - George Orwell.

Thanks for the suggestions. I've done a bit more testing on the seats today and it is only the driver's seat that is not heating. I've booked it in next Wednesday so we'll see what the dealer says. 14.5MY SDV6 HSE Dynamic Indus silver/lunar/ebony 20" wheels, InControl, full-size spare, electric tow bar, adaptive xenons, adaptive cruise control, auto main beam assist. Gone: TDV8 HSE; Zermatt silver/ebony, 19" off road alloys, active diff, particle filter, tow pack (it was fun) BMW 730D SE (great car, sadly missed). Ford Focus RS mk2, Ultimate green, lux pack 2, bluetooth. The start of my mid-life crisis.
IN THE GARAGE: BMW i8 - the mid-life crisis continues and it's great fun.

Update after 'while-you-wait' appointment at dealer today (free wash, vac, wi-if and decent coffee, so not too bad a way to spend an hour). Heated seat - new heating pads on order and booked in to be fitted next week. They have to dismantle the seat to fit them, so could be interesting! Auto heated rear window operated by mist sensor in rear view mirror - "never heard of it; impossible for that to work!" So no suggestion as to why it is operating even though the switch is off (tell-tale light out). Interior misting up - no real solution other than to apply a software update which apparently was available for the heating & ventilation system; will see how I get on next time it rains and I've got a car full of passengers. Not the most conclusive of trips to the dealer... 14.5MY SDV6 HSE Dynamic Indus silver/lunar/ebony 20" wheels, InControl, full-size spare, electric tow bar, adaptive xenons, adaptive cruise control, auto main beam assist. Gone: TDV8 HSE; Zermatt silver/ebony, 19" off road alloys, active diff, particle filter, tow pack (it was fun) BMW 730D SE (great car, sadly missed). Ford Focus RS mk2, Ultimate green, lux pack 2, bluetooth. The start of my mid-life crisis.
IN THE GARAGE: BMW i8 - the mid-life crisis continues and it's great fun.

I think the auto heated screens have something to do with interior temperature vs exterior temperature. Reason I say is that they do not come on when I have used the pre heater, despite it being ultra cold outside.

Had the driver's seat heating elements replaced yesterday. All good so far - I no longer have a cold bum in a morning! However, dealer unable to shed any light on heated rear screen and interior misting issues. 14.5MY SDV6 HSE Dynamic Indus silver/lunar/ebony 20" wheels, InControl, full-size spare, electric tow bar, adaptive xenons, adaptive cruise control, auto main beam assist. Gone: TDV8 HSE; Zermatt silver/ebony, 19" off road alloys, active diff, particle filter, tow pack (it was fun) BMW 730D SE (great car, sadly missed). Ford Focus RS mk2, Ultimate green, lux pack 2, bluetooth. The start of my mid-life crisis.
IN THE GARAGE: BMW i8 - the mid-life crisis continues and it's great fun.

Is it possible you have a very small leak in one of the seals round the windscreen etc which may be letting damp air in? 2010 TDV8

Thanks for the suggestion. No sign of a leak - no damp carpets etc. 14.5MY SDV6 HSE Dynamic Indus silver/lunar/ebony 20" wheels, InControl, full-size spare, electric tow bar, adaptive xenons, adaptive cruise control, auto main beam assist. Gone: TDV8 HSE; Zermatt silver/ebony, 19" off road alloys, active diff, particle filter, tow pack (it was fun) BMW 730D SE (great car, sadly missed). Ford Focus RS mk2, Ultimate green, lux pack 2, bluetooth. The start of my mid-life crisis.
IN THE GARAGE: BMW i8 - the mid-life crisis continues and it's great fun.