Janitrol/Goodman furnace - The furnace is cycling on and off, all the way up until the blower should go on and then it cycles down and after a couple of minutes it begins to recycle.

Sometimes the gas stays lit for 5 seconds and other times for a minute then when the blower turns on, the gas goes out. When it recycles 2 -3 times it sometimes works.

I also noticed the vacuum hose coming from the pressure switch sometimes is clogged at the blower in the furnace. If I unclog the line it fixes the problem, but not always. I have replaced the pressure switch already.

I have a Janitrol GMP075-3 furnace.

Please help!

How old? Have it inspected please... The failure rate on a GMP075 over 8 years old is nearly 100%. Failed heat exchanger that is. Carrier is under a huge class action law suit and may not be able to be sold in 7 US states. I sure wish this happened to Goodman, 5 years ago. I have 5 service techs, averaging 6 calls per day, we condemned 3 out of 3 Goodman furnaces last week.

The furnace is about 5 years old and it is 80 % efficient and it's natural gas. I keep finding the vent pressure switch vacuum hose is clogged at the fitting going into the blower. I need tips to dismantle and give it a thorough cleaning. I hope this would solve my troubles.

Thanks for the input NorthernHeat!!

My guess is the problem lies in the pressure switch. There is a very small vent hole on the pressure switch very near the barb that the hose attaches to. If the inducer doesn't pull a little fresh air though the line all the time it is running, these nuisances are more prone to happen.