"My heater shut down for an unknown reason to me. I called Hillside in the evening - told them it was not an emergency but would need a serviceman in the morning. Without fail - Hillside called me early and had a repairman in my home by 9 am. He did a full check and found the problem, replaced the part and my heater has been humming and running 100% since. Thanks AGAIN Hillside Oil - GREAT JOB!!"