Dryer is exactly 5 years old. It takes a while to dry clothes. I have had this problem before so I did clear out a clog in the vents. In fact there was a dead bird in the tube from the dryer to the wall. But I cleaned everything out including the link chute assembly in the dryer. I did notice that when I first turn on the dryer, there are flames in the heater box. They stay on for about 4 minutes and everything gets red hot like it should. Then after 4 minutes the flames go out. In exactly 55 seconds a will see a glow from the bottom of the heater box but no flames like when I first started the dryer when it was cold. The glow only stays on for 5 seconds. Then in 55 seconds it comes on for 5 seconds and this happens over and over again. Any thoughts? I sometimes think that the original clog might have caused another problem.