Performed Heating maintenance on a pair of Lennox furnaces. Both systems are equipped with icomfort white series thermostats that are functioning well at this time. Heating temperature splits are within range at 30 and 45 degrees. Condensate lines are clear, duct runs are sealed. Electrical amp readings are in range and recorded. Gas valves are operating within spec. Homeowner has Tesla installed surge protection on 1 entire system. Customer wants to install surge furnace protection on his own. Both systems were operational at end of appointment.