Work Performed: Service call for Weil-McLain natural draft boiler – complaint of no water pressure. Results: - Found water inlet valve in the closed position; opened valve and repressurized system - Upon pressurizing, backflow preventer began leaking heavily — removed and inspected unit - Existing backflow preventer was seized and leaking; replaced with new backflow preventer from truck stock - Verified proper system pressure and operation after installation - Performed combustion analysis (required annually by law) — combustion readings within safe limits - Observed one supply-side gate valve not opening fully; recommend replacing the remaining gate valve on the opposite supply loop - While boiler was operating, confirmed lack of return water flow through that zone, verifying the valve is stuck closed - Thermostat found loose on the wall and intermittently failing to operate due to broken mounting tab — recommend replacement with a simple single-stage heat thermos