9 yr old Kenmore 90 series dryer wont heat

is it gas ? next time open dryer door and send full model number if it heats for a while you have bad gas coils,when you change them out watch out for the coil with three prongs on it,there is a metal piece that sometime gets stuck in old coil when you remove it,if it happens just poke it out of old coil and slide it back on post where new coil will be installed

salde386 is correct. I had the same issue with my Kenmore 90 series. My dryer would get hot for about ten minutes and would not get hot again. I changed the gas coils/solenoids and that fixed my problem. Hope this helps. Here is a pic of where are they located --> http://ww2.justanswer.com/uploads/applsvcgirl/2008-01-22_173331_Gas_Burner.jpg