Upon arrival, found house temperature below setpoint despite boiler cycling normally. Discovered partially closed valve on return side above pump causing restricted water flow, which led to system overheating and short cycling. Opened valve to restore proper circulation. Also identified plugged backflow preventer preventing system from automatically adding water when needed. Verified boiler (GL Series AWR105ENS72PSU, 105,000 BTU/hr input) is fully operational after adjustments.
