Have had concord 80 plus system for 6 years and had problems with ingition , flame sensor , system remaining lit after ingition turnoff, several motherboard problems, ignition wire problems and assorted problems with the initial installation of the unit. After 6 years of marginal if not poor use from the unit I have spent around the same amount of money on service techs labor charges as I spent on the original instilation of the unit. Techinal support could not even help solve the problem after 3 hours on the phone with my service tech. Of couse my orriginal service tech did not report my orriginal problem so there is no papertrail for warenty information. Anderson (the concord manuf) was of little to no help and basically said tough... not our problem. If you are having a similar problem you will probably get stuck with a poor product like I did. If you need help... you can try the tech support line at 1800-448-5872 but do not expect much sympathy or actual help. They do not perfer to speek with the homeowner. they perfer to speek to service techs. .......better luck in the future.