Why don't they match

I think this may qualify as a trivia question. I use ResScan & Sleepyhead daily to follow my progress. I don't usually check on the screens on my S9 because the sw is giving me everything I'm interested in. Today I happened to look at the unit itself & found a Used time of 511 hrs & a Run time of 598. Shouldn't they be the same? I do have the auto start feature enabled so it's not my forgetting to shut the machine down. I know the S9 was brand new when delivered to me because I opened the box & removed the packing material myself. It's not very important but my oc personality wants to know.

The S9 machines run for 30 to 45 minutes or so after you quit using them in the AM. Very low pressure that you may not even realize it is happening. This is supposedly to help dry out the hose or whatever.
The low level pressure used minutes is counted in the run hours but not in the therapy hours because you aren't hooked up to the mask and machine.
So Run hours won't equal therapy hours unless a person totally removes electric source from the S9 every day exactly when they turn the machine off as far as their use is concerned.

Pugsy wrote:The S9 machines run for 30 to 45 minutes or so after you quit using them in the AM. Very low pressure that you may not even realize it is happening. This is supposedly to help dry out the hose or whatever.
The low level pressure used minutes is counted in the run hours but not in the therapy hours because you aren't hooked up to the mask and machine.
So Run hours won't equal therapy hours unless a person totally removes electric source from the S9 every day exactly when they turn the machine off as far as their use is concerned.

Thanks Pugsy, that's totally understandable. I now need to find another minutiae to stress over.