My high tech Lennox HVAC system would not not start cooling and was throwing out codes to the control thermostat that indicated a problem with the DC inverter circuit board. David came to my house promptly and diagnosed the problem. Fortunately, he found that the part was still under warranty and obtained a replacement from Lennox the next day. After installing the new board, the system reported that Lennox had provided the a board for a smaller unit so it so it was not compatible. David had to go back to Lennox to get the proper board and reinstall it. Then it finally worked. David had to do twice the work, thanks to Lennox, but he only charged the original labor estimate for installing the board once. On top of that, he noticed a picture of me in uniform and then offered me a 10% military discount!
I have worked with several HVAC companies in the past and Kahl is by far the most honest, reliable and responsive company I have ever worked with!