Arrived on site to perform furnace maintenance on 1998 comfortmaker heater. Upon arrival both homeowners were not present and daughter was only home for whole visit. Begin safety inspection and Maintenance on Heater and within the first 10 minutes of the maintenance the system already overheated. Client has already replace ignition box and indoor blower motor inside of furnace. Found that 1 inch filter was heavily restricted in causing system to be choked off. Also measured static pressure on system and found that airflow was at 0.77 WC which is way over the 0.5 it’s rated for. There’s major Airflow restrictions in the system due to an undersize return vent and king return duct as well. At this time system is continuously overheating and recommended that heat exchanger is inspected for safety of everyone in the home. Brian would like to hold off on the heat exchanger inspection and expressed that We Care did the same thing last time and shut off the gas and this is the reason why t