To avoid any build-ups of deposits I suggest using distilled water.
The day we got the oven it’s all we used (distilled water). BUT it leaked… till this day it leaks. I contacted them and they said that due to back log that I would have a wait to fix my leakage.
This is also mentioned in the manual.
Not having the Oven (no room) excuse my suggestion if erroneous.
However, I clean (by temperature) my brewing kit with white vinegar, I also use it on other kit before rinsing with plain water.
I use it to periodically clear car screen & light washer jet nozzles of crud, as well as dipping my chrome shower head in a container of it once per year, (I live in a hard water area of the uk, attached a low voltage mains “device” (by permutti) onto the copper incoming pipe which keeps the deposits in a suspended “slurry” state (far less calcium in taps, tanks etc) …our house pipes took a year or so to break down all the previous 32 years of calcium build up & the 1980’s hot water tank is more or less as clean as a whistle inside too.
Consider all options especially if you hate cleaning (or the smell of vinegar)