Wood stoves not getting air is a serious problem due to insufficient heat and health concerns. Inadequate air causes incomplete combustion, which defeats the purpose of using a clean-burning wood stove in the first place. So, why is your wood stove not getting air?
A wood stove not getting air is usually due to a weak draft, clogged chimney or flue, and negative pressure inside the room. Also, a stove’s air supply vents, their controls, and the type of wood you use play a vital role. Surrounding conditions may also have an impact.
All wood stove manufacturers have specific instructions for the proper installation of components like the chimney. Improper installation or inaccurate specifications interfere with a wood stove’s performance. In this article, I’ll elaborate on these issues and the causes for your wood stove not getting air.
Why Your Wood Stove Is Not Getting Air
A wood stove isn’t a complex appliance on the surface. But if you refer to your wood stove manual, you’ll find comprehensive instructions about the chimney diameter, size or height, dampers, etc. If your wood stove is inaccurately installed, it can have several problems.
For example, the firebox may not get sufficient air. Your stove may not burn the wood completely or cleanly, causing unburnt volatile compounds and flue gasses to accumulate in the appliance.
Also, improper installations are a hazard, which is why manufacturers recommend that the job be done by technicians certified by the National Fireplace Institute. So, you should inspect your wood stove installation, chimney, and other parts on top of the following issues.
The Flue or Chimney Draft Is Weak
The hot exhaust air and flue gasses from the wood stove rise through the chimney, creating a draft. This draft naturally draws air through the supply or inlet vents of the wood stove.
But if the chimney draft is weak, the wood stove won’t be able to draw sufficient combustion air.
The flue or chimney draft may be weak due to the following reasons:
- Soot and creosote buildup
- Closed or blocked damper
- Oversized chimney or flue
- Negative pressure in a room
- Windy conditions outside
- Mild ambient temperatures
Therefore, inspect your wood stove and chimney to ensure the entire system is clean. Ideally, you should clean the flue or chimney routinely to prevent soot and creosote buildup. Also, you have to do a full chimney sweep at least once a year.
If you have an oversized chimney or installation issue, consult a certified technician. A weak draft due to structural problems will only get worse if the outdoor conditions are unfavorable due to things like surrounding temperatures or wind.
The Room Has Negative Air Pressure
Most homes have reasonably effective insulation, making them almost airtight. The lack of fresh air circulation creates negative pressure inside a house or room. This negative air pressure increases when you operate a wood stove.
The chimney draft should facilitate the flowing out of hot exhaust and flue gasses. This becomes difficult, however, when the negative pressure inside a room or home tries to draw air in from outside. In effect, the chimney serves as the conduit for outdoor air to flow in naturally to attain a pressure equilibrium.
Furthermore, this negative pressure inside a room or house worsens if you have a bathroom fan or the kitchen hood running. As the chimney draft works in reverse or downward, a wood stove won’t draw fresh air in through its vents. Therefore, you have to address the negative air pressure.
Here are a few ways you can prevent or resolve the negative air pressure problem:
- Open a window slightly whenever a wood stove isn’t getting air.
- Turn off the kitchen hood, bathroom fan, and any outflowing forced air systems.
- Install an outdoor air intake duct or vent. Many wood stoves have this optional feature.
The exterior air intake vent or duct is a must-have fixture for any appliance that uses combustion, especially wood stoves and gas furnaces. An outdoor combustion air intake vent or duct essentially makes a wood stove immune to weak draft and negative air pressure.
The Air Supply Vents Are Clogged
I’m sure you’ve already tried toggling the air controls at the supply or inlet vents if your wood stove isn’t getting air. If the problem persists, go further and inspect these vents to ensure they aren’t clogged with ash, soot, and other debris.
Almost all modern wood stoves have at least two supply or inlet vents. Some wood stoves have three vents for:
- Primary air
- Secondary air
- Tertiary air
These vents should be open and regulated for sufficient airflow. Check if any vent is inadvertently closed or partially open. Also, ensure there’s nothing inside the firebox blocking the airways.
Check your manual or the signs on the wood stove to know how to regulate the air controls. Wood stove manufacturers don’t have identical maneuvers for their air controls’ open, close, and partial apertures.
The Local Conditions Aren’t Ideal
Some conditions aren’t ideal for wood stoves and chimneys. These include:
- Strong winds and local low-pressure formation
- Mildly cold temperatures in early fall or late spring
- Natural and other obstructions around the chimney
Left unchecked, these can cause the entire system to become vulnerable to a downdraft or reverse airflow through the flue.
Windy conditions and moderate fall or spring temperatures are temporary issues. However, any significant obstruction near or surrounding the chimney can cause a chronic backdraft problem. So, check these parts if your wood stove hasn’t been getting air for some time.
A clean chimney and wood stove shouldn’t have a weak draft unless the negative air pressure in the room is unusually high. So, keep the dampers open and regulate the wood stove’s air supply or intake vents, as necessary. Also, keep the door slightly open after you have a small fire to provide more air. At this point, there’s no significant chimney draft to allow the wood stove to draw air through the vents. Last but not least, don’t use green or wet wood on the stove.