Common Causes Of Odours From Furnaces

Furnaces Odour Causes

Whenever you switch on the furnace, you can expect a breeze of warm air to begin regulating your house’s indoor temperature immediately. What you might not be thinking of is range of odd smells which waft in as the furnace operates.

Heating units can give strong and strange smells off. A few of such odors will solve by themselves and should not cause you any worries, while others can indicate a potentially hazardous issue with furnace. Identifying the probable cause of scent can assist you take right steps for freshening your air.

Below are the most common causes of any abnormal furnace odor.

Cracked Components

The furnace as a system may last for considerably longer than a few of its individual parts. For example, lots of furnaces suffer a cracked heat exchanger. When the heat exchanger gets damaged, gap releases chemical smell which can resemble formaldehyde. Get your heat exchanger replaced immediately since this problem can result in furnace inefficiency, carbon monoxide problems and fires.


If the furnace sits in damp parts of your home, this moisture might settle on the system. When furnace turns on as well as gets hot, the dampness starts to burn off and that can create smell of dampness all through your house. Luckily, this smell should resolve itself when the furnace carries on to run.

Excess of Dust

During off-season, dust might collect on and in your furnace. When you start to heat your house for the very first time in the year, your furnace likely will burn the dust. If heated air smells like dusty for short time period, the odor must dissipate quickly. You also can avoid this smell by simply dusting the furnace off before turning it on.

Gas Leakages

Natural gas utilized for heating is generally treated with sulphur in order to offer it its rotten egg smell. The odor is designed to alert the homeowners to prospective gas leakages as quickly as probable. If you smell the sulphur, leave that area and contact a heating expert technician along with your gas company.

Intake Contamination

Lots of furnaces intake air from the home’s outside. Anything that’s within proximity to the intake system can potentially alter characteristics of the heated air. For instance, if the furnace smells similar to sewage, that odor probably comes from sewer system opening which is near the intake system.


If your heating unit becomes obstructed, one among the very first signs you’re probable to see is change in the air smell. The kind of obstruction determines resulting odor. For instance, a blocked chimney might make the furnace smell as if it is smoking, while any pest struck in your system will smell like a decay. Usually, you’ll have to turn the system off and have it evaluated to resolve these problems without the risks of incorrect furnace venting.


Along with gas leak-related smells, you should never ignore electrical, sparking or hot metal odors. Such smells generally indicate a problem with overheating and might point to a defective auto-shutoff.

Old Filters

The furnaces are outfitted with inner filters that assist regulate the quality of air in your house. Over the years, the filter can get clogged with debris and dirt. Not just can a clogged air filter affect efficiency of your heating unit, but you also may smell the obstruction too.

An older furnace filter might smell somewhat as motor oil. But, you must be alert that if changing filter doesn’t get rid of smell, the system could have serious oil leakage, which needs professional attention by Bothell Heating.


furnacefurnace repairfurnace repair near meheatingheating repairheating repair near me

Leave a Reply

Your email address will not be published. Required fields are marked *

Call Now