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Which HVAC Smells Are Normal for Your Unit?

Your home’s HVAC system is very complex, requiring regular maintenance work and upkeep to run at its best. In addition to watching for performance issues, you should also pay attention to HVAC smells, as they can indicate many different issues that can require professional care.

HVAC Smells and What They Mean


These odors are caused by mold or mildew growth in your HVAC system, likely in the ducts. This is due to condensation collecting and not draining properly. Among HVAC smells, it is one of the most common.


A burning smell is quite dangerous and can indicate there is damage to important HVAC components such as the fan or the compressor. If you smell burning, turn off your HVAC system and contact a professional HVAC servicing company as soon as possible.

Rotten Eggs/Sulfur

The smell of rotten eggs can indicate a gas leak, as the odour is added to gas to allow for leak detection, as natural gas itself lacks an odour. If you smell rotten eggs or sulfur, alert your local gas company, open the windows if you can, and leave your home immediately.


A gas smell can indicate one of two things: If you’re turning on the furnace for the first time that year, it can merely be the heat exchanger burning off any dust that has collected since the last time you used it. However, if the gas smell is not coming from a vent, it can indicate a pipe leak, and you should contact an HVAC professional.

Call a Professional to Address HVAC Smells

At Arpi’s Industries, we serve homeowners in the greater Calgary area, helping with all their HVAC needs by offering experienced and professional care to every customer we serve. We know that a strange smell coming from your HVAC system can be quite concerning, especially when you don’t know what it is. If you have any strange HVAC smells, contact us today and we can help find and fix the problem.