A few weeks ago during a cold weekend evening my furnace had issues so I called Knight to send an after hour furnace tech to troubleshoot my furnace. After an hour the tech showed up and 30 minutes later after trying to troubleshoot the issue. The furnace started up on its own, and the tech admitted he had no idea what the issue or the solution was. I reluctantly paid the $250 bill (after hours call plus 1/2hr labor) as nothing was identified as a problem and more importantly nothing was fixed. Furnace again had issues the next day and after some googling i removed and cleaned the fire sensor, cleaned the ignitor rail, blew out and cleaned all of the tubing lines. Took about an hour but the furnace worked great until this morning. Additional troubleshooting and a free conversation with another company led to the real issues which was a failed flame sensor. $25 for the part and 20 minutes later, my furnace appears to be running great. I've cycled it many times tonight without issue. I have no issue paying for help from professional services but the charges from Knight for the after hour service call and labour was ridiculous considering he didn't even figure out what ended up being a simple replacement. Very very disappointed in the service. Take a look at the picture attached.. I'm pretty sure any furnace service tech would have at least checked the flame sensor condition before packing his bag and leaving.