Arrived onsite to perform the hvac maintenance. Customer has an 11 year old Buderus boiler, she explained that the boiler made some banging noises last winter other than this no additional complaints. In the attached form is a list of measurements I performed today. Outside of this form I confirmed that the heat exchanger is very clean, condensate trap is clean, all gaskets are in good shape. Venturi is in good condition, checked combustion, and gas pressure, these numbers are within range. Relief valves are closing properly. Performed a crawl space inspection, no leaks were present. Unable to hear any abnormal noises. Thank you for choosing CPI Plumbing and Heating Inc.