After checking many complimentary reviews, we called Richard at 6am, he returned our call very promptly and advised that he would be with us between 11am and 1pm. Upon his arrival he was very friendly, asking several questions about the problem before heading up into the attic. Seeing that there was no power to the unit, he started checking the possible causes and came across a switch that disintegrated as he removed it- probably the answer to the problem. He did not have the part with him, so headed to Lowe's and returned 20 minutes later; installed the new switch and it has been running perfectly ever since. Absolutely fantastic service at a reasonable cost - we will definitely use him again in the future and highly recommend him and his company.