The blower of my furnace makes a loud noise every time it starts. I understand that a large fan and the movement of large amounts of air will produce some noise. What I am puzzled by is the noise that sounds like a "starter." The noise only lasts for about a second or two; then there is just the expected sound of blowing air. Could it be a motor failure problem at its infancy, or could it be related to the capacitor start on the motor? The blower pushes air without a hitch. Is this a normal condition that is heard on all blower motors? My system is a direct drive motor driven, "squirrel cage" type fan, hot air, oil fired furnace. I am aware of the sounds of the fuel pump and then ignition of oil rumbling in the fire box (I don't know if that's the right term) but anyway the sound that I am trying to troubleshoot is the noise when the fan motor starts (my best description is that of a car starter) It may be spelled RRen-nen-nen-nen and then just the sound of moving air after the fan gets to full speed.

There is a capacitor on the motor, could it be a malfunctioning capacitor? I have lived in an apartment building for 30 years and now in a single family dwelling, and have never heard any heating system noises. My concern is in what to replace; motor & capacitor, or just motor, or just capacitor or is that just a noise that I am going to have to get used to? Maybe you have a belt that is slipping. It might make noise until the blower starts spinning. It you have a belt, check the tension. The controller circuit for your furnace (usually a little box to the right of the motor with lights, a reset button, and some wires connected to terminals) is responsible for the operation of your furnace. It handles the motor that pumps air and oil, the flame sensor inside the unit, and the ignitor. The ignitor is a gap between two metal poles and runs at high voltage in order to create a spark between the poles (and thus plenty of heat). The order that things start up (motor or ignitor first) varies between controllers.

Either way, the first few seconds of operation involve the motor and the ignitor running until the fire starts or the controller decides it has been potentially spraying flammable liquids for too long without seeing a fire. It's likely in your case that the ignitor is running, then the blower. The blower is louder. I've had controllers that run the ignitor before the blower and after the blower. What type of fuel does your furnace use? furnace blower motor noise startupI have an oil burning furnace, and when the oil first ignites, there is a "whomp" noise from the sudden expansion of gasses in the burner box. fan coil unit advantages disadvantagesThis happens at the same time that the blower motor turns on, and could easily be mistaken for coming from the blower or motor.mr slim split system air conditioner

Browse other questions tagged hvac electric-motor or ask your own question. NOISE – An air conditioning system starts making an unusual noise.  The noise may be generated from the indoor or the outdoor unit. NOISES FROM THE INDOOR UNIT – Typically, noises generated from the indoor unit are caused by some type of problem in the blower system. Bad Blower Bearings - Qualified Technician Recommended Broken or Loose Blower Wheel - Qualified Technician Recommended NOISES FROM THE OUTDOOR UNIT – Typically, noises generated from the outdoor unit are caused by vibrations or metal objects coming in contact with each other. Fan blade out of balance Object in the fan path * Do not attempt to remove anything from the fan guard while the unit is operating. Bad Fan Motor - Qualified Technician RecommendedOil burner noise, odor, performance or smoke troubleshooting: Some oil burner noises are normal, others indicate trouble - we explain the difference.

We also explain how to recognize & diagnose the cause of oil fired heating boiler noises, leaks, odors, or soot and smoke. We describe just about any noise that you might hear at or near an oil burner, where it comes from, what it means, and what needs to be done about it. This article series answers most questions about central hot water heating system troubleshooting, inspection, diagnosis, and repairs. Some heating system and heating oil burner noises are considered normal. These include noises coming from the following items: The sketch above is provided courtesy of Carson Dunlop Associates. Noises & soot buildup can lead to a potentially dangerous puffback which can damage the heating equipment and blow soot and smoke throughout the building. An experienced heating service technician may recognize the following diagnostic list of heating system or oil burner noises as well as perhaps other signs of trouble: Heating equipment located well out of occupied space, in an unoccupied basement, for example, are not usually a source of noise complaints in

a building, though there are a few exceptions for which we have suggestions. Articles at this website describe how to inspect, troubleshoot and repair heating and air conditioning systems to inform home owners, buyers, and home inspectors of common heating system defects. Continue reading at OIL BURNER NOISE DIAGNOSTIC FAQs for additional examples of oil burner noise sounds and their cause, or select a topic from the More Reading links or topic ARTICLE INDEX shown below. Or see OIL BURNER ODOR DIAGNOSTIC FAQs - odors often occur together with noises at oil burners and can help diagnose one another Or see HEATING SYSTEM NOISE DIAGNOSISDoes your furnace remind you every time it's running, by offering you a "Bang" or a "Squeaky, squeaky, squeaky"? Sure, we are glad the furnace is on, but who wants the life scared out of them, or to have to turn the volume up on the TV to "Mega-Loud”? More often than not, noises from a furnace and duct work are simple to fix, and can be remedied rather easily with household items or small purchases from the local home improvement store.

Let's take a look at some of the noises a furnace makes, where exactly they come from, and how to fix them. Does Your Furnace Bang Every Time it Comes On?The wonderful "wha-boom" noise you're hearing when your furnace comes on is likely one of two things. It could be your duct work doing what’s called “oil-canning,” that is, flexing when the pressure changes, or less likely but more serious, it could be a small explosion called a “roll-out.” Possible Cause 1: Oil-Canning Duct Work. Go to the furnace and listen carefully at different places, to see if the banging is coming from some place in the duct. If your duct is oil-canning, it likely has a weak spot and needs support. You can easily fix this oil-canning by screwing a slightly thicker piece of metal across and onto the spot. Though it may sound silly, you could even whack that spot with something to dent it in, though I don't recommend this being your first choice. Possible Cause 2: Ignition malfunction (roll-out).

This is not very common but can be scary—a little explosion when the furnace starts up, or a burst of flame bigger than it needs to be. To see if banging is caused by a gas ignition problem, watch the furnace start up. Leave the doors on the furnace so that you aren't affecting the observation. If you can see into the furnace doors, you should be able to see what is happening. If not, listen, to pinpoint where the noise is coming from. Watch to see if the doors on the furnace shake at all. If so, then try again with the door to the burner compartment open, to see if the banging still happens and if you can see what happens when it does. If you see extra flame or shaking associated with your noise, the good news is that you've identified a potentially dangerous problem in your home and can now correct it. The bad news is that you will most likely need help correcting the problem; messing with the gas portion of your furnace is not recommended. You may feel better to know that newer furnaces have a “roll-out sensor” that will shut down the unit if this problem occurs.

Is Your Furnace Whistling?If your furnace is whistling, ask yourself, "Did this just start, or has it always whistled?" This will help determine what you should look for first. Possible Cause 1: Dirty filter. Especially if this whistling has started recently, check your filter. It may be clogged and causing the fan to suck air from anywhere it can. Even tiny holes or spaces will whistle if any significant air is being sucked through them. To test this theory, pull the filter out and see if the whistling stops. If your filter is so caked with dirt that it is clogged and stopping the flow of air, you are better off just taking the filter out (while you arrange to go get a new one). This is better not just for the noise but also for the wear and tear on your fan motor. Possible Cause 2: Gaps in the duct. Try to hear where exactly the whistle is coming from. It will likely be a small hole near where the duct connects with the furnace close to the blower. To resolve this problem, tape up the gaps, with foil tape or duct tape, or use clear hi-temperature silicone to seal them off.

Possible Cause 3: Ducts too small. If the whistling stops as soon as you take the doors off the furnace, it may have gone away just because you've opened up the unit and relieved the suction that was being created. If you can’t find any another cause for the noise, it could be a sign that your ducts are improperly sized; your furnace wants a greater flow of air. Do You Have Rattling in Your Furnace and Ducts?Vibrations and rattling are simple fixes usually. Here are a few things you can do to stop these annoying sounds. Add more screws to loose ducts. Add rubber or cork pads under the unit where it sits on concrete or blocks. (Yes, you can likely raise the unit with a pry bar just enough to slip something thin in there.) Do Your Ducts Bang or Squeak When You Walk on the Floor?Possible cause: Duct work not secured right. The duct may be too tightly secured to the ceiling below you, or the metal panning may not have been nailed up correctly. Either reinforce the duct, as with an oil-canning duct, rehang it, or replace it with "Thermo-Pan.”

Do You Hear Whooshing?Possible Cause: Not enough air coming through. Is the air passing through the registers (the screens that let hot air into and out of your rooms) just plain loud? You may need some duct resizing or additional return air added to your system. This will quiet things down. Temporarily, use a cheaper filter—a more permeable filter, with more and bigger holes-- and change it often to keep it clean. This will allow more air to pass through the blower. Do You Hear Motor Noise?Possible cause: Old motor bouncing, or wearing out its bearings. Walk around and listen to see whether the sound is coming from a motor. Try to describe the sound it’s making; this can be useful to anyone who may assist you. In some cases, an old unit may be weak and allow the motor to sort of bounce as it runs. You may be able to place a sturdy piece of styrofoam under the squirrel cage to stop this, but if the bearings themselves are the culprit, you may need to call a professional.