leak in chimney

[texastele]

Is there any way to check to see if there is a leak in the chimney? We have had the CO detector go off twice before (once with a fire and once without), so I am not sure if there was a leak or not. I changed the battery but we had not had a fire since then I thought that I would look into this while I had some time before wood season got here in force. Thanks.

 

[zogger]

Details?

Is there any way to check to see if there is a leak in the chimney? We have had the CO detector go off twice before (once with a fire and once without), so I am not sure if there was a leak or not. I changed the battery but we had not had a fire since then I thought that I would look into this while I had some time before wood season got here in force. Thanks.

What kind of chimney? What sort of access?

Or are you asking is there any way to like pressurize it or vacuum test it...geez..I guess it might be possible, but I have no clue how to go about it.

Usually visually is the answer, with a strong flashlight, and sometimes if you can access it in the attic, say an old fashioned brick and mortar chimney, you can feel for air leaks or use a "puffer", a little squirt gun looking thing that puffs smoke, the liquid smokes when it hits air. My dad used to have one of those for working on old mainframe computers, they needed to test for airflow all the time.

They also make a little swizzle stick looking tool that has like lightweight tinsel on it. They are very sensitive to airflow and will move around in the slightest breeze. Any local hvac supply will maybe have one. About pencil sized. And dang if I can remember the actual real name, which is embarrassing as I used to own one and used it when we were remodding homes to be more airtight, but that's what it looks like, a little stick with tinsel on one end. It is used for the same purpose, detecting air leaks in general. Just hold it close to a suspect area and see if the tinsel moves.

With that said, why suspect the chimney if your carbon monoxide alarm went off when your heater wasn't running? Maybe your hotwater heater (if it is gas or propane) or something else is doing the leaking.

Or quit giving bowzer your leftover burritos...

 

[laynes69]

When there's draft there should be no spillage. If a chimney is too big or cold, a draft can reverse down the flue during a low burn or coaling stage. It will be hard to find anything this time of the year. How tall is the chimney and what size of flue does it have? Exterior chimneys can have this happen. Also a partial blockage or creosote can cause it. Good thing you have detectors. Also check other appliances in the home.

 

[texastele]

It is a full size brick and mortar chimney on an exterior wall. It is a full size fireplace. I am not certain what you mean about the flue; I did not know there were different kinds. I just reach up and trip a lever and the door opens. It is a one story house and the chimney goes up about seven feet above the roofline. I had cleaned it (sort of-with rigging up my shop vac), but plan to have it cleaned professionally. Maybe he will tell me there was a lot of creosote in it. I think that the problem occured when the fire was going out for us to go to bed, but I can't remember exactly. Drafting could be the problem.
I did not think that it was a problem with one of the appliances due to its lack of happening again, but it could be.
Thanks

 

[stumpy75]

A good chimney sweep should be able to check out your chimney and tell you if that is the problem. Although I could clean my own, I have one out every year to get a second opinion on whether I have a problem or not. I do this at the beginning of the heating season, and then check and clean it myself if needed sometime in early January.

With a fireplace and a large masonary chimney, it would be possible that you might have a cold air plug when starting a fire, and that could cause some smoke back into the room, but carbon monoxide is caused by incomplete burning. I guess it's possible to come from a wood burner, but I would look at other appliances that are operating at the same time. The draft of the wood burning flue added to the draft of other appliances in the house(water tank/furnace) might be more than the makeup air coming into the house. This would cause a backdraft of the weakest draft, which probably would not be the wood burner.