My mother has COPD and purchased the rhythm healthcare p2 oxygen concentrator. After 7 months of use it is making terrible noises and has an alarm that will not stop. The alarm warning states that O2 is less than 87%. After contacting 1st class medical; they informed me that the concentrator was under warranty & it would take 4-6 weeks to repair. In the meantime we can rent a loaner for $390. My mother is still making payments on the P2 and is on Medicare/social security. How do you expect for her to pay for this as well. Why should she have to rent a unit while still paying for the original one. Plus it's under warranty!