Called out for water leak in furnace room. Plumber was out and said it was related to the furnace/flue. Water pan for water heater is full of water and underneath has moisture- possible crack in pan or adapter for water heater drain line. Pulled off shield to water heater and found more water Internally on shelf and seam of water heater is rusted indicating water heater is leaking. No water streaks are on top of water heater or around furnace/furnace water safety pan. Went in attic and verified flashing was secure for flue and found no water streaks indicating flashing was loose. Addressed second issue of low airflow to NW bedroom. Airflow is present but cfm is low, unable to access ductwork to that room due to space constraints in attic.