I am having the same issue with my York furnace, red light blinking 3 times. It has been very cold at night, kids are freezing, could anyone help us out??

Jpho, on the inside of one of the removeable panels you should have a diagonistic chart that will tell you what "three blinks" mean. Good luck

According to this York Furnace Error Codes | eHow.com 3 red falsh is normal operation. Carefully check again or have another person observe. Bif dif between 3 flashes and 4 with a York

parttime, the 3 blinks appears to represent "pressure switch stuck open". What is a pressure switch and where is it located?

york pressure switch - Google Search

Here's a link, should look something like this. Good luck