Question About Resmed S9 Total Hours

Is there a way to verify the total hours used on a Resmed S9 Autoset (like an odometer)? I see run hours in the clinicians manual but was wondering if these hours used reset when the CPAP is reset or if the "run hours" are always cumulative even if it is reset?

'Run hours' is cumulative and cannot be reset using the "Erase Data" function the way "Used Hrs" can be reset.

In general, always check the condition of the machine for dents and scratches, look for dust in the intake, feel the crispness of the buttons, smell for smoke free environment, etc....