TeemuFIN

Yes, that most likely explains my issues with electric pre-heating. I just did not use it enough to actually figure this out I'm gonna rephrase my opinion on the aux heater: If you need pre-heating only when charging the battery, then aux heater is not worth the cost. But if you want to pre-heat also when charging is not possible (traveling, etc), then definitely aux heater is worth the cost.

I've had once a situation where radiator fan has been on by itself when car is in the parking lot, powered off. When I entered the car and switched the power on, I started getting errors from all assisting systems (travel, side, etc). Car did refused to start and radiator fan did not stop. I switched the power off and fan stopped then. I would guess that if the fan blows on full power, it will run the battery empty quite fast. And yes, if the 12 V battery runs empty, it will ruin the battery permanently.

Something to remember about any fuel-fired heater is that, depending on the usage pattern, their life time is somewhat or very limited. If you use heater often but only on short bursts (<15min), it will develop soot(not sure about the english term?) in the combustion chamber, shortening the life span. It is very well possible that you ruin the heater already in three years. Off course, of the car is a 3 years lease, it won't be your problem, then

I have the option in my Octavia IV PHEV and I have not used the electric pre-heating much as it seems to be inefficient. I don't know if it only uses the power from charging cable (I had the 1,8kW option only available when I tried it) to pre-heat or actually the batteries but I barely got the car to warm a few degrees at departure. Now Webasto heats the car _really_ quickly as it only heats the interior, not the engine. usually 15 mins seemed to be enough to bring the cockpit to +21C at any outside temperature. Off course the mobile app problem exists with aux heating, too. Unless you preprogram the heating/charging from car, using the mobile app as remote control is very unreliable way to start heating. I've installed Webasto ThermoConnect to control the heater directly and that works each time. But is it worth the price? After my experience with Skoda mobile app and electric heating, I'd definitely say "yes", providing that you can use the radio remote or install some other means to control the aux heater.

My new iV PHEV had Oil Change interval 15 000km(9320 ml)/365 days when I got the car.

Anyone yet pulled apart the boot fairings? I was trying to locate the Webasto heater receiver (T91) and it's supposed to be on the left side in the boot but I was not able/did not dare to loosen the fairings. There's two screws on the plastic hooks at least but do you have any additional tips on how to access under it? And yeah, I haven't had a new car before and definitely have not pulled apart anything from such