When I turn the furnace on the pilot flame comes on and the burner does not fire.
The pilot will cycle on and off a few times and then quit. This is an itermittent problem
that is becoming more frequent. The unit is only 3 years old. Thanks for any help.

Clean the flame sensor. See if that will allow the furnace to stay running.

There are different styles on different units. Also be careful if you have to get around the ignitor since they can be easily damaged.

Thanks for your help hvac1000. My furnace
has been working perfectly now for 24 hours.

Good deal and I am glad you got it going