Why isnt my climate air tubing warming on manual setting?

[Pamg]

I have used resmed machines for 7 years.  I started with a 10 which worked great for 3 years.  I use climate air tubing set to maual temp of 85-86 and humidity about 6-7.  The last 4 years I have literally limped along due to the problem of my tubing not heating properly. Or really not at all.  The warmth from water chamber isn't enough.  Cold air gives me headaches. I've tried switching old tubing, new tubing,switching outlets etc.. nothing worked. My provider would send another machine, worked for a short time,same thing again,stops warming. My last machine was an air sense 11.  It constantly rained out during the night. Tubing never warmed. Just got another 10, tubing heated perfectly to 85 degrees for 2 nights then stopped.  My provider insists NO OTHER COMPLAINTS FILED about this issue which I find suspicious.  Does anyone have these warming issues so I know I'm not crazy!  I just want a reliable machine.