Karlo Z has done the preventive maintenance for our oil boiler several times and he is always very professional and very friendly. He always takes the time to answer our questions and to do a thorough check of our system to make sure it is operating at peak efficiency. When we recently noticed a small amount of oil under our tank, we contacted Burkholder’s for a service call, and Karlo made sure he was the one to come to check our system. He found a leak in our 60 year old oil tank, took pictures, and arranged for an estimate to have the tank replaced. We’re grateful to Karlo for his thoroughness and friendliness.