Adequate Air Supply: Adjust the stove's air vents and consider slightly opening a window in the same room when starting the fire to introduce fresh air and help balance the pressure. Regular Chimney Maintenance: Ensure your chimney is clean and free from obstructions.
The surest way to overcome the stack effect is to provide a directly ducted source of outside air to the combustion air inlet of the appliance. This isolates the combustion and venting systems from the rest of the house.
In extreme cases like yours it is possible that during an overnight burn when the stove is turned down, draft can collapse and stack effect can pull smoke out of the stove. Once this kind of spillage starts, it can quickly become a full hot backdraft.
So the best way to prevent poor draft is to always keep a bright flame burning in the firebox when there is available fuel to burn (not just coals). This will keep the draft up. Heat in your flue is what powers your stove, so when the flue cools, it can't pull as much air into the stove.
If you live in an old home, it is possible that your chimney might be too short. Short chimneys cannot vent properly, it should at least be three to four feet tall. Soot and burned debris buildup can narrow passageways for the smoke to escape through your flue.
Too much draft may cause excessive temperatures in the appliance and may damage the internal components of the stove. An uncontrollable burn or excessive temperature indicates excessive draft.
Backdrafting is a health, safety, and comfort concern. To prevent it you must either build a house without a chimney, or balance all the ventilation systems to prevent indoor-outdoor pressure differentials. In short, houses need to inhale as easily as they exhale.
Stoves that backpuff or smoke at start-up are extremely annoying, but fortunately the cure is simple. You need positive draft in your chimney when you light the fire. Without positive draft to pull smoke up the chim- ney, the smoke from your fire will just build in the firebox until it eventually spills into the room.
Using a fan to circulate heat
It's one of those immutable laws of the universe, but that doesn't mean you can't move it around. A fan sits on top of your wood burning stove and the heat from your stove will cause the fan to spin (no need to plug anything in!) and subsequently move the heat around the room.
If the water heater is backdrafting, you will feel the warm, moist air escaping from the draft hood. If you want visual confirmation, you can take the small mirror or glass and hold it up to see if it gets fogged up from the warm air.
Installing a chimney cap will help prevent flue obstructions and downdrafts. A chimney cap with a mesh screen will also keep curious critters from getting trapped in the flue. Periodically check to ensure the chimney cap is secure and replace when damaged.
If there is an obstruction in the venting that interrupts the airflow, negative pressure builds in the flue, causing a backdraft forcing the smoke and fumes back down into the living space. Negative pressure can occur when there is a flue obstruction or insufficient air is being drawn into the fireplace.
For a stove to work, your chimney needs to be drawing air up, creating suction and pull to draw the smoke around the baffle and up the chimney. If your chimney is not drawing well, it cannot create enough suction and it will force smoke down the chimney back into the room.
Shut Off Exhaust Fans: When your fireplace is in use, turn off your exhaust fans, as they naturally increase negative pressure by pulling air out of the house. Adjust Your Damper: If your damper is warped, you might need to adjust it slightly to get the right airflow.
Poor Air Supply in the Home
This problem is often easy to identify. If you recently had new doors or windows installed, and then noticed a back-puffing issue, try introducing airflow to the fireplace when it's burning. Open a nearby window before you start your next fire.
When lighting your stove, open both air vents fully. On initially lighting, it can be an advantage to crack the door open slightly to provide additional air flow through the firebox. Once the fire is established, close the door and then close down the bottom air vent gradually.
Adequate Air Supply: Adjust the stove's air vents and consider slightly opening a window in the same room when starting the fire to introduce fresh air and help balance the pressure. Regular Chimney Maintenance: Ensure your chimney is clean and free from obstructions.
Solutions to Fixing Backdrafting
One great way you can fix back drafting is by installing a water heater backdraft preventer. Much like a backdraft preventer used in sewer pipes, a water heater-specific backdraft preventer forms a gate-like structure.
The most common tactic used by firefighters to defuse a potential backdraft is to ventilate a room from its highest point, allowing the heat and smoke to escape without igniting.
All stoves in homes built after 2008 require either an air vent or external air intake, regardless of heat output. Without it, the stove may struggle to draw sufficient air for clean, efficient burning. Even in older homes, a stove can benefit from an external air kit.
Installing a wind-directional chimney cap can help prevent downdrafts by redirecting the wind upward, regardless of direction.