Yesterday Keith came out and did a great job. I later called since I heard a sound coming from my furnace that I had not before. Today Nick came out and found it was due to the wrong filter I put in. They did not charge me for this second call. I am a Crystal Club member and over the years I know I can rely on Black Diamond for excellent service! All of their people are wonderful - from the people in the office to the technicians. All polite and friendly and careful about listening to all my concerns.
