How to Fix Chimney Smell in the Summer

Putrid smells emanating from fireplaces are customers’ number one complaint during the warmest times of the year, according to Jason Raddenbach of CleverlySolved.com.

“Folks use their fireplace all winter long, and now the summer humidity is making their chimney extra stinky. Then the A/C draws that smell right past the metal damper and into the house. They get the chimney cleaned, and it makes it smell even worse,” he says.

What Makes a Fireplace Stink?

One of the primary reasons fireplaces reek in hot weather is that creosote (a tar-like byproduct of wood combustion) and ash have saturated the chimney during heavy winter use. The chimney comes into contact with the muggy outside air which reacts with the acidity of the creosote. The result is a stench that can permeate an entire home.

If a chimney is open or poorly sealed (a loose-fitting damper or glass doors), every time you turn on the dryer or bathroom fan it creates negative pressure that sucks the smelly air down through the chimney and right into the living area.

What To Do If Your Fireplace Stinks?

The problem is real but there are things you can do (and not do) to eliminate fireplace funk when temperatures and humidity rise.

Don’t clean your chimney

Cleaning your chimney will only make things worse. “I know it is counterintuitive, but cleaning your chimney right now is the equivalent to shaking up a carton of spoiled milk and popping the top, says Raddenbach. “You should get your chimney cleaned, just not during the summer.”

Don’t install a top-seal damper

A top-seal damper will only bottle up the foul odor and keep it from off-gassing into the outdoors.

Seal off your chimney low and tight

You can use fireplace plugs or other draft stoppers to prevent downdrafts and force the house to find a different location through which to draw air.

Deodorize the firebox with baking soda

After removing loose soot and ashes from the firebox, sprinkle a box or two baking soda — coating the floor, walls and damper. Leave it to set at least 48 hours (or even up to a week) then vacuum it up.

Tip: Lightly spray the sides of the firebox with water to help the baking soda stick to the vertical surfaces.

Try the vinegar bowl fix

Neutralize odors by placing a large bowl of white vinegar in the firebox for a day or two. This will also help get rid of that “burnt” smell.

DIY Energy Audit

A house is a system that breathes, and when an HVAC system, clothes dryer, range hood or bathroom fan is running, it affects the airflow in and out of the house. Along with trying the above ideas to deodorizing your fireplace, having an energy audit performed on your entire home will help determine how well this system is working and if there are ways to improve it.

If you’re DIY-minded, here’s how to do a rudimentary check yourself.

1. Turn on the clothes dryer. This is a great way to create negative pressure in the house.
2. Use a smoke pencil to conduct a draft check. Take the smoke pencil and puff around trouble spots like windows, doors, pipes, vents and other places where air is likely to penetrate.
3. Seal them up. If you discover leaks and drafts, seal them with foam or caulk.

Note: Never use a lit incense stick or cigarette to detect drafts because you could easily drop ash on your floor or scorch your curtains. “The first rule of any successful DIY project,” says Raddenbach, “is to use the right tool for the job.”