How often do you replace your humidifier chamber?

I have spares of most consumables--purchased when the DME seemed most needy.
This way I am covered because they are never open at night or on weekends--
when bad stuff always happens.

Have had to train both my DME's to only send me supplies when I get in touch. And then only to send what I ask for. Last time around, with a new DME, I requested nasal cushions for my mask, and they sent a heated tube, filters, and nasal cushions...everything went back to them except the nasal cushions, which was a pain. They said that from now on they'll only send what I request *smile*. We'll see.

If you let the average DME run open loop, they'll send out the maximum supplies Medicare (or your insurance carrier) will pay for on the Medicare replacement schedule. On the original question, the only time I've replaced humidifier chambers is when I actually needed to, not a believer in replacement schedules. If you only replace things when they need to be replaced, and your DME is on a replacement schedule, you can end up with way too many spares. Personally, I'd rather store those excess spares at the DME's place *smile*. I also want Medicare to be able to continue to function, having them overbuy really isn't helpful to that purpose. So it behooves you to make sure that the DME knows what you want, and observes your choices.

My DME has offered to send my supplies to me, but I prefer to drive 15 minutes to their store,
and only get what I want.
Edit: And now, they need two weeks to order my hypoallergenic filters.
Once again, they asked to ship my supplies to my home--and and I declined.
I live right in town! When I go in, I will claim credit for saving them postage.

They are right next door to two of my favorite stores, so, not out of my way.