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Why Does My Furnace Smell Like Cat Pee?

If your furnace has a weird smell, like cat pee, you may be wondering why and what you can do about it…

Why Does My Furnace Smell Like Cat Pee?

Your furnace could smell like cat pee due to some kind of obstruction or interference with your ventilator registers, or your air vents. It’s possible that your cat either went pee on or near the vent, and a simple clean of the area surrounding the vent should make this smell go away. 

There is also the potential that some mold or mildew is growing either in or around your furnace or in your air ducts. This can be very harmful to your health, so having an HVAC technician check for things like mold is worth it before dismissing it as your cat has an accident.

How Can I Prevent My Furnace From Smelling Like Cat Pee?

Brown steel boiler hanging on a white wall.

Brown steel boiler hanging on a white wall.

You don’t want to cover up vents, so making the area surrounding them unsuitable for your cat is the best way to prevent them from making your furnace smell like cat pee. You should avoid placing litter boxes near an air vent as well.

Using an enzymatic cleaner or a concoction of baking soda and vinegar can help you get rid of the scent around your vents, and will hopefully prevent your cat from peeing near that area again.

How Can I Clean My Furnace?

How you clean your furnace will depend on what type it is, but essentially, wiping down surfaces and components appropriately and changing the filter frequency can help you keep it nice and clean. You’ll just want to make sure you turn it off before going to clean it. If the thought of cleaning your furnace on your own scares you, you could always call an HVAC specialist to help.

Will The Smell In My Furnace Ever Go Away?

The smells coming from your furnace should go away once you tackle the issue causing the smell. Sometimes this means you need maintenance or need to replace your filter. Making it a priority to keep your furnace maintained with regular cleaning can help to prevent odors from lingering in the air or coming back.

If you haven’t used your furnace for some time, there may also be a temporary dust smell that you can sense as soon as the air begins to flow through your home. This smell will go away fairly soon after.

What Does A Bad Furnace Smell Like?

Bad furnaces can emit a very pungent, unpleasant odor, often compared to the smell of sewage or rotten eggs. This smell is an indication that something is likely wrong with your furnace’s heat exchanger. If you detect this smell, turn off your furnace immediately and contact someone to look at it.

These sour and strong scents are not only gross, but they are signs of a serious concern that, if left undealt with, could cause your furnace to leach out dangerous carbon monoxide into your home.

The same is true of chemical smells or a burnt electrical or chemical smell; this indicates that carbon monoxide could be developing or leaking and you need to turn off your furnace, get out of the house, and call an HVAC technician.

Is It Normal For Your Furnace To Smell?

There are some smells that your furnace will make that are somewhat normal, especially if it’s been out of use for some time. Most of the time, a strong and unsavory smell isn’t normal and requires further inspection.

There’s a good chance a smell that lingers or hits your nose furiously when you get near your furnace means something is going on internally, so you should shut it off and call someone for service.

Can You Spray Febreze On A Furnace Filter?

A spray bottle of Fabreze.

A spray bottle of Fabreze.

Febreze can be used on a furnace filter, though you’ll get the best results if you spray some Febreze on a new filter as you’re doing a filter change. This spray can not only help push a pleasant, fresh smell throughout your home, but it can also be another protective barrier to keep bacteria and junk out of your air filtration system.

How Often Should You Change Your Furnace Filter?

Your furnace filter needs to be changed every three months at minimum; think of it as changing your filter at the beginning of each season. That said, some people may need to change theirs more or less often based on several factors, such as the size of their home or who lives there.

If you have pets in the home, especially multiple, you might find you need to change your filter a little bit more often. If you purchase thick filters, you might find you don’t need to change them as much unless you have multiple pets in the home.

What Smells Can Come From A Furnace?

Furnaces can emit some strange smells, some of which are very good indicators of specific furnace-related concerns you should be aware of. As mentioned, rotten eggs or sewage is a very dangerous smell. A must smell could be an indicator of a water leak in the furnace, and the smell of car exhaust could mean an obstruction that could lead to a carbon monoxide leak if not dealt with.

The smell of burning plastic or dust, as mentioned, is common when turning on a furnace after its summer break, and that should dissipate within a day or so. Checking that your filter is in good condition isn’t a bad idea when you smell this, just in case.

What Can I Boil To Make My House Smell Good?

Simmer pots are a fantastic and simple way to add a waft of freshness and pleasantries through your air without using chemicals or fake scents. If you are noticing the smell of cat pee, boiling some cinnamon and citrus can add a nice aroma that is strong enough to cut through that signature ammonia smell that cat pee contains.

Lemon and lime peels with a splash of vanilla or mint can also create a beautiful aroma throughout the house that can also cut through a cat pee smell or other strong and unpleasant scents.

Lindsey Browlingdon