Cleaning oil reservoir without oil change

Thx all!  Oil change and reservoir cleaning it is. ?

It is crucial to adhere to the oil purging protocol after removing the oil tank and exposing the oil system to prevent potential valvetrain problems. I recommend watching this instructional video on how to properly execute the oil purging process.

https://www.rotax-owner.com/en/videos-topmenu/expanded-video-instructions/33-exp-si-912-01813

I find that if you drain and open up the oil tank just be sure to tie up the oil outlet hose fitting so it never drops below its normal installed height, and do not turn the prop. The inlet hose from the bottom of the engine can be left dangling as low as possible to thoroughly drain the crankcase. If you do this, no oil purge procedure is necessary after you refill and reinstall the hoses.

I have no experience of crankcase oil heater that are being discussed. I am curious -

how cold must the weather be, before considering the use of such a devise?

what temperature can they deliver (how hot does the oil get)?

can the temperature be adjusted (say to Rotax min take-off of 50C)?

do they usually work on a timer?

how long ( for a 912ULS/3.5 litres of oil) ) does one have to be on for, to raise the oil temperature to a satisfactory level?

how/where is the heater fitted?

I’m using the EZHeat system on my motors which is a heating pad on the crankcase and another on the oil tank. It’s controlled with a relay activated with a text message and I use it when it’s below 50 degrees and it warms the oil up to about 75 degrees and makes for easy starts. When it’s 30 degrees I’ll go for 3 hours and 40 degrees about 2 hours.