A visual check is one of the surest ways of checking whether the damper is open or not. Simply stick your head in the fireplace and look up. If you have a throat damper, the closed damper immediately above your head will block your vision. You should be able to reach up and touch the closed damper.
In reply to SI A: bit of brute force. poke it with sticks etc. if it's totally jammed use poles on top of a hydraulic car jack to forcefully break up the bottom layer af blockage. be prepared for it to 'go' very suddenly and violently. wear masks and goggles and probably hard hats would be wise.
To check for a blocked chimney flue, light a small piece of paper or kindling and hold it near the opening of the fireplace or stove. Observe the direction of the smoke. If the smoke flows freely up the chimney, the flue is likely clear.
Carry out a visual inspection of the chimney from your fireplace. If you can see open dampers or see the sky, that will prove that the flue is open. Failure to see the sky implies a closed flue or one that may need unclogging.
Warm air (smoke) will rise, and is lighter than cold air, so why isn't the smoke going out the chimney? One of the simplest checks is to just feel if cold air is coming down through the flue. If it is, the flue may need to be warmed up before starting a fire.
Signs of Clogged Flues
If you see rust or water streaking on the vent, flue, or on your chimney, something may be blocking the flue. Moisture builds inside your furnace pipes when the air can't properly circulate, and this can result in rust. Soot around your furnace is also an indication of a problem.
Push the blockage down the flue using a wire chimney brush with the same diameter as your flue. You might get lucky and dislodge it with a couple of prods. Other times, you'll need to cajole the clog down to the fireplace, adding extending rods so the chimney brush can reach.
Lubricating the flue mechanism can help loosen stuck parts and make it easier to open. Depending on your flue type, you may need to use a silicone spray or graphite powder as a lubricant.
If you don't feel any cold air coming down the chimney, it means that the damper is closed. Another way to find out if the damper is open is to do a visual check. If your chimney has a traditional damper, all you need to do is shine a flashlight up the chimney. If you can see the sky, it is open.
Cleaning of the chimney's flue can be done from the roof or through the fireplace. You'll need a wire brush with an attached extension for this task. After removing the rain cap or animal guard, reach into the chimney with the wire brush and scrub the inner walls of the flue with an up-and-down motion.
Inside a chimney you'll find one or more vertical passageways called flues. Ideally, each appliance connected to the chimney (such as each fireplace, each furnace, each wood stove) has its own, separate flue. More than one flue might be contained in one masonry chimney.
It's best to keep the flue closed when the fireplace is not in use. Should it stay open for too long cold air, debris, rain, and even animals can make their way inside your home.
Again, their lifespan depends on routine maintenance and usage, but it's common for metal chimney liners to last up to 25 years. Cast-in-place liners are the most robust because they're typically constructed from cement, and with proper care, you can get up to 50 years from a cast-in-place liner.
the ball should be slowly lowered from the flue outlet to the bottom of the flue (the fireplace recess or the appliance connection) where a blockage or obstruction is found, it must be removed and the test repeated until the flue is completely clear of obstruction.
Clean the chimney cap with a scrubbing brush to remove any debris. Proceed to inspect the inside of the chimney with a flashlight. Use your brush to clean out the top portion of the chimney, either by pushing or pulling out the debris. When finished, put the chimney cap back on.
Inspect your fireplace's flue prior to use for any obstructions or blockage by using a flashlight and looking up the flue. This also assures that the flue's damper control is open prior to lighting the fire. Keep anything that can burn at least three feet away from the fireplace or wood stove.
A blocked flue, or one in poor condition, could put you at risk of carbon monoxide poisoning (although being unable to access the flue doesn't automatically mean that it is unsafe).
If you are suddenly experiencing poor chimney draw, it might be that you've got a blockage in your flue. It could be a creosote build up from the smoke or it could even be that a bird has set up their nest in there! Either way, it not only affects your chimney draft, but also puts you at risk of a chimney fire.
1- Priming Your Chimney
All you have to do is locate the damper on the inside of the unit, open it, and place the burning newspaper as close to the hole as possible. Estimated burn time should be between 2-3 minutes to effectively prime the chimney. Please Note: Be careful when placing or holding the burning newspaper.
One of the simplest ways to block up a chimney is simply to add a piece of plywood to the interior of the chimney, just above where the fireplace ends. This can typically be fitted by hand but getting it to stay in place can be tricky.