I have a carrier furnace (around 4 years old). I can hear the flame click on but the fan never starts. It goes for about 5 seconds and then clicks off. It does this over and over in three minute intervals. It eventually takes but it goes through 40 or 50 false starts before it finally blows...
It's a cruel and expensive world. My wife Sara and I are true DIYers. We'd love to call repair people every time something goes wrong but we'd be afraid to bounce the check we paid em with.