Performed a heating maintenance. Changed the nozzle filter and strainer. Cleaned the heat exchanger and flue pipe. Inspected electrical connections. Adjusted electrodes. Bled the oil line. Started and tested. Combustion test was 34ppm at 3.4%o2. No smoke on the smoke test. Replaced the pump flange that was leaking for the domestic water heater loop. Purged that line. Boiler psi is 22. No other leaks found. Customer is paying for the landscaping shop maintenance also.