When heater is on but wont blow hot air out couple weeks go by n it comes on n goes back off couple hours later

What is your question?

when u start the car it doesn't come on for days then all of sudden it comes on and blows out hot air for couple hours then stops working.n won't work for week n then come on its sporadically coming off n on.

What makes this problem better or worse?

nothing seems to work it comes on when it wants to then goes back off

How long has your 2004 Lexus RX330 had this problem?

It comes n goes