I have Lincare that supplies my large oxygen machine and a Poc oxygen. Thid year was the 5 year year where Lincare was to replace old machines with new machines. The big oxygen machines seems to be working fine. The POC when the guy delivered it bever set it up ir anything, un wrapped it was all ge dis and it was wrapped in plastic wrap. Thus was like 3 months ago. I went away for the weekend, and when i tried usung the machine at bedtime the a alarm get going over every mintues, thus was on continuous flow, alarm read "low on purity flow". So i tried it on pulse, it seemed to work ok untill 4am then same thing alarm going off every minute. Looked at manual, and it was a Xerox copy, and stapled, some pages upside down, lousy copy. I dont think this was a new machine, i rhunk it was used and never serviced, didnt even have any extra filters. Shouldnt the machines they give you be new? And birmt refurbished?