The only time I feel heat is when I relight the furnace but it will only work for about 45 minutes then no more heat but the fan would still keep going and blowing cold air. I've had my father-in-law come over and we were both working on it but still the same problem. I'm down to calling an professional but found this site and was wandering if anyone has had or would know how to fix this problem.

What brand of furnace and how old is it? We will take as much info as you can give us.

Sorry for not getting back. I had some unexpected relative that just showed up at the last moment and was bussy the hole weekend, but it's a janitrol and I think its about 10 years old but not really sure. It does have a board and does light it self. I did also had a few minutes to look at it and notice that the flame keeps going out about an hour or so after I light it. A coworker told me it might be the board and to shut the breaker off for a few minutes and turn it back on but it still isn't working.