My gas furnace started making a loud when it comes on..What could be the problem?

Jane A
by Jane A
It is a Goodman brand\furnace\air conditioner and has was put in about 10 yrs.ago
  15 answers
  • Loud what? Banging sound? When did it happen? As soon as the thermostat called for heat, or when the fan began blowing the air? Can be a few things. Fan inducer motor may have failed. Or blower that moves the air may have become loose or is out of balance. Or it can be from what is known as Oil canning. I suspect that its oil canning which is why I am talking about this first. Oil canning is when the return air duct gets sucked in when the blower turns on causing a loud banging noise as the metal flexes. Then when the furnace is turned off it bangs again when it returns to normal. This can happen if there is a remote filter in a wall or ceiling elsewhere that may be plugged with dirt, Or a blocked return grill somewhere else in the house. You can check to see if this is the noise by having someone turn on the furnace while you watch the air ducts that go into the bottom of the furnace. If they move in and out when the system turns on and off this may be the reason for the noise. If the furnace is vibrating and making banging noise when fan runs, it may be caused by something that got stuck in the fan blades. Perhaps the filter may have become dislodge and part of it is in the blower. Just a little piece of paper in the blower can make it go out of balance quite easily and make a racket. If you suspect that this may be the cause you need to do the following. Turn off the furnace at the safety switch. Then remove the bottom panel on the furnace to expose the blower fan. Then carefully reach around the side of the blower that the filter is located on and feel the blower blades with your fingers. Be careful as they can be sharp. But feel around as you slowly turn the fan with your hand. You may find a small piece of paper or part of the filter trapped in the blower cage. Remove it and put cover back on furnace bottom and turn it on to see if this noise has stopped. The fan inducer motor can make noise as well, but quite often then not it fails and the furnace does not even run.
  • Jane A Jane A on Nov 28, 2011
    The loud noise is when the fan starts to blow and the filters seem to get sucked in.
  • you have a restriction in the duct. The noise is the oil canning I described. If your using high capacity filter and they are installed in the rooms rather next to the furnace they are to restrictive or plugged with dust. Remove them and see if there is any difference with the noise stopping or not. Its common for people to use the electrostatic type filters thinking they are making the air cleaner. These filters oftentimes comes as black plastic that are adjustable in size by cutting and installing a frame around them. The issue is here that not enough air will get to the furnace as the blower struggles to overcome the resistance of these types of filters. When this happens not only does the ducts collapse and make noise as your experiencing but the furnace runs hotter and tends to cycle on the high limit control which shortens it life and raises the concern of failed heat exchanger.
  • Yea, as usual I agree with Woodbridge. Let me tell you this though, just the simple fact that it is a Goodman furnace should have you concerned. If it is a air restriction this makes the heat exchanger more prone to fail as he said but in the ten year old Goodman models they don't need any help failing. Goodman products are horrible, always have been and on the models they made between 10-16 years ago the heat exchangers would crack for no good reason. I have condemned more of these furnaces then any other models that have been made in the past 25 years.
  • Walter Reeves Walter Reeves on Nov 28, 2011
    I love the phrase "oil canning" and know exactly what you mean......my Dad's oil can made a little "ta-dink, ta-dink" noise every time he used it lubricate motors.
  • I started putting in Goodman condensers when they came out in the early 80's Sold a bunch of them to people who wanted a cheep way out when their older condenser failed. I put one in at a home about 15 min away from my house. Got it running cleaned up when home to a phone call from the client saying the system was blowing warm air. Went back and found that a screw in the cabinet from the factory had pierced the coil in a spot that was not repairable. Contacted the supplier and all they would do for me was provide me with a new coil. I had to eat the cost of removing the old, changing it out, and doing all the work to get it running again on my dime. Tried to get a new condensing unit figuring it had only ran about 20 min. But to no avail. Never sold another one or recommended one of these units to this day.
  • Jane A Jane A on Dec 01, 2011
    The motor was going so we had it replaced...Thank you all for the rapin responses........
  • Glad your all warm and toasty now!
  • CR Draves . com CR Draves . com on Dec 01, 2011
    A loud _____? Sounds like it could be anything... need more specific information about this. Gas furnace: Up draft, down draft, wall heater, efficiency heater, convention natural gas. When it calls for heat, do you hear the IBM (little blower motor) taking out the unwanted gases first. Then you should hear a click releasing for the circuit to go through the safeties. Then some sort of ignition source, then a click to open the gas valve, finally lighting the gas. In two more minutes on a time delay, the big blower motor. If it's not doing this in sequence, you could have a bad circuit, circuit board, ligniter, gas valve, or blower motor. My best guess is that your blower motor is going bad if it's a loud ____________? C.R. Draves
  • CR, guess you missed her reply. The contractor replaced the motor. My guess it was the frame that cracked that supports it. Anyway. Great response. U know your stuff.
  • Mike wylie Mike wylie on Jun 20, 2013
    I have a Goodman furnace and AC. After the AC is on for 1-2 hours the furnace starts making a loud noise and the AC is not working well. The furnace seems to freeze up and there is water evident at the bottom of the furnace?
  • You are low on refrigerant in the ac system. When that happens the coil above the furnace gets so cold instead of cooling the air and removing moisture it freezes the moisture causing the water to turn to a block of ice. IN turn this stops the air from flowing out of the ducts. Turn off the AC unit and turn on the fan on/auto switch to on. This will keep the air blowing and help prevent any more water to leak onto the floor. It will take about an hour to melt. DO not run the ac until you have the system professionally checked. Or you risk burning the system up.
  • Dev Tony Dev Tony on Jan 04, 2014
    furnace started making noise and was told heat stopped coming up have recording of noise, gas furnace conventional
  • Cozy Home Service Cozy Home Service on Jan 06, 2014
    Send me the sound bit. Usually if makes nose then no air blowing sounds like motor or blower problems.
  • Rudolph Palmer Rudolph Palmer on Dec 09, 2014
    My Furnace making loud puffy hesitant wwhhOoOF ! flame when thermostat kicks back on ?