1999 Honda Civic Heater Not Working

assuming that you bled the air out of the system, find the heater hoses and check their in/out temperature

Same problem hear hoses are both not What do you think problem is eating me

Civic's engines are heat deficient, especially as they age. They just suck at making enough hot coolant in the winter especially if you're stuck in slow moving traffic or the car is parked. I flashed the system, separately heater core, checked thermostat, OEM coolant and not much of improvement. On the other hand 01-05 are known as head gasket blowers. Old Toyota Tercel also sucked in the winter until Toyota developed Echo-Yaris engine which IMO is one of the best small engines. So, engine block heater might be good addition to have the engine warm after cold winter night and reduce warm-up time in the morning. Make sure that flaps in the air box and heater coolant valve work properly, '99 up have electric motor for moving the flap doors.