GOING OUT TO DO HEATER MAINT. ALSO RENEW CC. HE ALSO STATED THAT THE THERMOSTAT THAT WE INSTALL IS NOT WORKING PROPERLY. HE STATED HE TRIED TURNING ON THE SYSTEM AND IT DID NOT WORK. FILTER IS AN APRIL AIRE 213 (THIS IS AN ADDITIONAL CHARGE)-AK SUGGEST DUCT CLEANING & OR DRYER VENT CLEANING. CAN YO DO ANYTHING BETTER TO IMPROVE SYSTEM & WHOLE HOUSE???-TK