Had Lisco out twice this winter one time to replace a bad igniter and once to replace the control module. I called them on this past Sunday because the heat was not coming on again. The tech (think it was TJ) came to the house and checked it out. turned out to be a dirty filter which he asked me on the phone if I changed it recently. In any event he checked it out and didn’t even charge for the call. I believe this is a good honest company and trust them completely.