nebulizer

you can find invacare dealers in your area from this URL
http://www.invacare.com/cgi-bin/imhqprd/inv_dealer/dealer_Main.jsp?s=0

just enter your zip code and a map will come up with several close by dealers.
you can also call 1-800 333-6900 for invacare service line .. they can probably direct you to a local dealer/service ..

there are several filters in the machine that have to be changed periodiclly .... the outside filter is washable and that should be done every week or so ... there is a large (probably square) filter inside that just plugs in .. if that clogs then it will flag an error and maybe shut down .... normally thats a service technician job .. however its not hard to change if you are handy with that sort of thing ... there is another small antibacterial filter .. (about 2 inch disk between two air hoses) that should also be changed every few years .. .if any of these filters are clogged then it will flag an error ... on some machines there is an oxygen purity detector .. if the oxygen content of the output drops below a preset value (maybe 80%) then that flags an error but probably wont stop the machine .. all of these things can be taken care of with normal servicing (if you can find reasonably priced service in your area) ... be careful not to run the concentrator in a kitchen while things are cooking .. the fumes, grease and stuff get sucked into the machine and that can clog the big Square filter rather quickly ...before you call for service you need the model number and the number of hours .. there is a meter somewhere (usually in back) that gives you the number of hours on the machine .. these things can run 30,000 even 60,000 hours before they need an overhaul .. you might want to check your local laws .. sometimes you have to have a prescription for the oxygen concentrator .. there are lots of companys that overhaul these things but at about 50 pounds or so, its kinda bulky to pack and send ...