We have a Harman p38 that we bought in 2007. Stopped blowing hot air yesterday, cleaned the esp probe today and was running fine. However, once the stove started running for a couple of hours I noticed a weird chirping sound coming from the back of the stove. Turned the stove off, cleaned it, removed the panel and blew out any dust, etc. Started the stove back up and within a couple of hours the chirping sound is back. Any ideas? Could it be a bad distribution motor? I thought I read that Harman has a five year warranty on their stoves. Would this be something that is covered? Only heat in our downstairs and about to get hit by a noreaster so any info would be greatly appreciated!