1. Ur air suam is room temp or luke warm?    Ambient = Room temp (usually 26°C), 40°C = luke warm

2. Ya same, the button is there in case u want to do it manually (i.e. outside the scheduled timing)

3. Roughly 15~20 min, but usually our technician set it at midnight 3am when no one is using and it just run auto so u probably wont notice

4. Outlet sterilisation = Flushing the outlet with hot water (in addition to the hourly UV sterilisation), since hot water will flow out, need to put a container before starting the process, that's why can only do it manually. Suggest do it once a month 

Point 1: Ambient water is same temp as your ambient. Air suam is usually warm water, hence LG Technician recommend this temp to you. Usually baby milk is mixed at this temperature.

Point 2: Internal pipe sterilisation in the app is the same as the physical button on the water purifier. Outlet sterilisation button will dispense hot water to sterilise the outlet spout, this will take 15 minutes to complete.

Point 3: High Temp internal sterilisation takes 15 mins to complete, and purifier is down during this period. It will take estimated about 2hours for cold water to resume (at max temp after sterilising). Usually my personal recommendation is to set this at mid morning or whenever the use of the purifier is not required.

Point 4: Internally there is UV light which sterilises the internal of the outlet spout every hour. This outlet sterilise flushes hot water to the water outlet, sterilising with hot water. If you frequently use hot water, this may not be necessary to be performed, again my personal recommendation is to run it once a month.

No worry, not stupid question 

Only 1 type of sterilisation is manual, the other 2 types are auto, so u dun have to worry bout them:

1. Internal pipe sterilisation auto weekly, to flush with hot water the machine's internal pipings

2. Water outlet UV sterilisation is auto hourly, to kill bacteria growing on its surface

3. Water outlet sterilisation (hot water flushing) is manual, cuz it uses hot water to flush the outlet, so must put a container

1 and 3 are both flushing with hot water, mainly to clean up any residue in the pipes or any dust on the faucet (since the faucet is exposed, flying dust may attach on it, even though UV alrd kill any bacteria, still need to clear the dust) 

nice. u chose the same model as me. i installed mine early jan also.

but now i wonder if i should have chosen WD518AN instead since it is a newer model plus the rental amount if exactly the same.

why u did not choose WD518AN also? just curious. 

1 and 3 are both flushing with hot water, mainly to clean up any residue in the pipes or any dust on the faucet (since the faucet is exposed, flying dust may attach on it, even though UV alrd kill any bacteria, still need to clear the dust) 

To ensure hygiene, it's highly recommended to do it once every 3 mths

Put a bowl there, press a button and takes bout 10mins to complete only, very easy 

It means ur filter needs to be replaced, have u receive it thru poslaju?

https://gscs-manual.lge.com/CWZ/MFL66990833...n.html#topic_21

Nope, but just:
1) Press and hold "Outlet Sterilisation" button for 3 sec, then
2) Press "Dispense" button

Yup, only 2 colors

To replace filter can follow here ya
https://www.youtube.com/watch?v=9OSM3-6H_78

Ya can, no need power off