Customer called for boiler with auxiliary domestic water tank not operating. Customer is scheduled for maintenance next Tuesday but it stopped working so we came out today. Upon inspection I found the high efficiency boiler to have a burned out control board. Found a big burn spot with resistor burned up. Upon doing research I found the brand to be discontinued and no longer available. This high efficiency system is also about 20 years old with outdated components. It’s recommended to replaced the full system due to these reasons. As I did some research I could not find most components through supply stores. We will cancel the maintenance appointment for Tuesday and follow up with new system quotes as well as options.