Burning Odor from Vents If you notice a burning smell coming out of your air vents while the furnace runs, these smells are symptoms that tell you the furnace blower motor is overheating.
Electrical Burning Odor
Electrical burning smells can be highly alarming. This odor could indicate an overheated blower motor. Blower motors commonly overheat due to clogged air filters.
A failing blower motor may emit unusual sounds. This may sound like screeching or squealing if it has bad bearings. You may hear a rattle or a banging sound if something inside the motor has broken or come loose.
Overheating or burning smell
If your motor is hotter than normal, or is starting to smell like something is burning, stop using it immediately and contact your repair technician.
A Failed Motor
An HVAC blower motor will occasionally fail due to age, wearing out, or not being cleaned regularly. Symptoms may include strange noises, burning smells, or just plain refusing to turn on. If this happens and the motor is no longer operable, a new blower motor may be needed.
If the blower motor is going bad, it will struggle to operate the fan. The result will be weak airflow coming from the vents inside your living spaces. This airflow issue can be one of the main symptoms that indicate the component needs to be replaced.
An electrical fire might smell fishy as a result of burning chemicals or insulation. An electrical fire smell is also comparable to a burning plastic smell. If you suspect an electrical fire in your home, contact emergency authorities immediately.
The combustion of your car's engine can produce sulfur dioxide, which drivers report as a horrible, strong rotten egg smell. When your catalytic converter is failing or stolen, it cannot filter these emissions—allowing the pungent sulfur dioxide smell to carry through your exhaust.
Some people describe this smell as similar to acetone, nail polish remover, or even chloroform. The odor may become stronger with larger leaks, but it's often subtle enough to go unnoticed. If you notice an unusual sweet or chemical-like scent near your HVAC unit or air vents, it could be a sign of a refrigerant leak.
Replacing a furnace blower motor costs $560, on average. Depending on the size and type of motor, most people pay $300 to $900. The average blower motor replacement cost is $560, but the final price depends on labor fees, as well as the cost of the parts.
Faulty Blower Motor
If your blower motor is experiencing some issues, you may hear a high-pitched squeal or whistling sound. You may also experience rattling and loud screeching noises. The motor blower pushes warm air out of the furnace through the ducts into your home.
Blower motors are designed to last just as long as your furnace itself, anywhere from 10 to 20 years. Just as with any HVAC system, the better maintained and serviced your equipment is by experienced HVAC technicians the longer it will last and the fewer repairs you'll face.
A "new fan" smell is rare but can happen. The smell is in no way harmful. Please run your fan on high speed for 24 consecutive hours, and the smell will disappear.
The temperature in an electrical fire can reach 1100°F in just 3 ½ minutes, which is high enough to melt home appliances, and burn plastic. This results in toxic fumes (1) that include ketones and aldehyde gases that are harmful to inhale.
Phantosmia refers to any smell you detect that isn't actually there. For some people, these odors are pleasant, like freshly baked sweets. But most people describe unpleasant smells, such as: Burning rubber.
If your car emits a rotten egg smell, there might be a problem with the catalytic converter, fuel pressure regulator, fuel filter, or even the old transmission fluid. Whatever the cause, if you get the rotten egg smell in your car, take your vehicle to the mechanic as soon as possible and resolve this problem.
Lack of use – the most common cause of smelly car air conditioning is from a lack of use. This can cause dirt and bacteria build up in the system, forming and growing in the air vents – and leading to a musty smell.
Electrical systems should be relatively silent. If buzzing, sizzling, or humming noises emanate from your outlets, switches, or electrical panels, these could signal a loose connection or problematic wiring. These sounds can be early signs of electrical fire hazards and should be addressed immediately.
Since CO has no odor, color or taste, it cannot be detected by our senses. This means that dangerous concentrations of the gas can build up indoors and humans have no way to detect the problem until they become ill.
The 'burning plastic or burning rubber' smell is a sign that the copper wires are heating up, and the heat is melting the insulation slowly, bit by bit. This is also a sign that the electrical fire has not started yet, but the copper wires are heating up.
On some platforms, a faulty blower motor relay will cause the blower not to work at all, which means there will be no airflow from the A/C. On others, the blower won't work on “high blow” but all the other speeds will work. The blower motor relay fails because it regularly deals with high current loads.
Blower Motor Resistor Test
Typically, if the fan will work on some speeds but not on others, the resistor is suspect. Okay, let's say there's no melting going on, but your fan doesn't work on all speeds. Typically, if the fan will work on some speeds but not on others, the resistor is suspect.
How much does it cost to replace a furnace blower motor? Standard Single-Speed Motors: $400 to $700. Multi-Speed Motors: $650 to $850. Variable-Speed Blower Motors: $750 to $1,250 or more.