Cleaning oil reservoir without oil change

I'm no expert but most of the oil is in the tank to start with, maybe 3 liters. I would do another oil change.

Why do you think that the tank needs cleaning?

If the oil temperature remained at an acceptable level (say 120C) the oil will be perfectly okay as will the tank- check out Rotax Max oil temperature (from memory 130C)

Hey Sean great question and one we have discussed.  After the heater being on for 10 days, what really concerned me was the smell. The only way I can describe it is the difference between when coffee is brewed, and when someone leaves the burner on for way too long……it was pretty bad.  Even though I can’t see into the reservoir, my concern was something bad happened in there. The other concern was just the lid on the reservoir was so hard to takeoff (heat?).

I guess you could call this the extremely conservative approach, but also if there’s another way , we are all ears

appreciate your thoughts ? 

No real way to tell about the oil unless you had it tested. Is it okay or not I'm not sure, but changing the tank oil is quick and easy enough. It's only a few liters of oil. Bottom line you couldn't go wrong by changing it.

It is rarely wrong to be conservative. Remember the saying " An ounce of prevention is worth more that a pound of cure".

If you’re using the semi synthetic oil then you probably cooked out the mineral oil portion of it over a ten day period. I’d dump it and spring for the three liters to replace it just for peace of mind.