Responded to service call for Lennox boiler system that was heating but not circulating water properly. Upon inspection, discovered the auto fill valve was shut off, preventing proper pressure maintenance. Restored system operation by opening the valve, bringing boiler to correct pressure, and purging air from the lines. Additionally, replaced a malfunctioning zone valve on the main level that was intermittently sticking, which had been causing continuous heating issues. Verified complete system functionality after repairs.
