2000 4 runner heater not heating up

my therm. and also flushed out and filled my coolant. My heater control valve seems to be working. Could my heater core be clogged? Could the sensor switch be bad? My window defrost are not working properly either. Help!!

Check to make sure radiator is full and overflow is filled to proper height. Sometimes after flushing, you'll have air in system and when system cools it will suck all the coolant from overflow. If there's not enough coolant then there will still be air in radiator. If full, remove radiator cap, start engine and let idle until engine comes up to operating temperature. You should be able to see coolant start to flow in top of radiator. This means thermostat has opened. If functional, install radiator cap and feel heater hoses at firewall. If one is hot and the other is cold then you don't have flow through heater core. This could be plugged core or defective control, depending on where control is. If you can see control and hose or tubing is hot past it (on heater core side) then core is plugged. If core is plugged, remove both hoses and fit a garden hose as tight against the return fitting as possible. (Return is the hose that was cold when other hose was hot) Turn pressure on and hope trash comes out. If so, flush for a while until clear then reverse flow. Repeat as necessary until clear and good flow in both directions.

my therm. and also flushed out and filled my coolant. My heater control valve seems to be working. Could my heater core be clogged? Could the sensor switch be bad? My window defrost are not working properly either. Help!!