Derrick, as always, did an outstanding job performing the semi-annual maintenance service. I was impressed and grateful that he isolated and corrected a clicking noise emanating from the airflow grille on the lower level. Derrick determine that the noise was related to a faulty filter, not a bad relay. This was a major relief thanks Derrick’s to his professionalism. Not stopping there, he seized the initiative to replace the water filter in my new Honeywell humidifier so that my HVAC system will be ready at the beginning of the next heating season. I am a fully satisfied customer of Dale’s Heating and Air largely thanks to Derrick.