I have Goodman Furnace model GMT 090- 3 installed in 1999 and it has stop working and when I open the cover of furnace I can see there is a red LED light that blinks three times and stops after a second or so it again blinks three times and stops this cycle is keep going, and furnace doesn't start. The diagnostics info on the panel says it's a pressure switch and to check the 'venter' for a blockage. I'm the 2nd owner and don't have a manual. What and where is the vinter and how does one check it or fix it? Thanks

The 'venter' or draft inducer is the small motor you see on the top of your furnace near the flue pipe (assuming it is an upflow furnace). As far as a blockage, well you can check the flue down stream. Could also be the inducer itself. Does it spin on a call for heat? Could be a failed pressure switch. The orifice on the pressure switch could have debris blocking it. There are many different options. Best bet is to call a local service tech on this one.

Just found out the expensive way,same thing,fan but no heat and shuts off after a few.turned out to simply be a clogged vacumum line from the fan to the limit switch,clean out the nipple on the fan.cost me $196 to find out,hope this will save $$