Recent Drafting Issue

[SouthcountyRI]

Hello everybody, been to the forum before, but finally had to sign up to see if I can get some help with an issue I've recently been having. Here's the deal, I bought my home (single story ranch) last April. I grew up in a home that heats 99% by wood stove, so I've always wanted to in my home as well, it's my first house, I'm 24. When I bought the house, it had the stainless double wall insulated chimney running outside a gable end of the house, and the old Warnock Hersey stove was in the basement, no stove pipe connecting the two. So last August as the burning season approached, I cleaned the chimney, rigged up the flue, made sure all my clearances were good, etc. I burned all winter without any issues, from late October until about mid March. I wouldn't say I burned 24/7, but more like 75% of the time due to work schedules.

The only issue I would have sometimes is that I would have to crack a basement window to get the stove to draft on a cold light up, I know I have a tight house, but It hasn't really posed an posed until now. Once I got the chimney warm, no issues. This winter here in RI nights probably averaged about 18 degrees and daytime probably averaged around 25-30. Twice in the past month, from mid March until now, considerably warmer outside, 50 degree days and nights about 25-30. I have let the stove burn out and approximately 30 hours or so from the last time I load it up, my monoxide detector has sounded. It is in the basement mounted on the ceiling (CO / Smoke combo) approximately 20 feet away from my stove. My house is all electric, both heat and hot water, so nothing else in the house creates CO besides the stove. Also, I have noticed that when I open the stove door in the past month, my flames want to come outside the door and the basement gets smoked out, where throughout the winter I did not have this problem. Even when I opened the stove door for a longer amount of time to stoke it, it would still keep drafting up and out, but now it seems to want to come out of the box. Besides that, there isn't really a drafting issue on a hot fire until a day after I let the fire die out.

My theory of the CO detector sounding is that when the stove fire finally stops making enough heat to pull a draft, it loses it and finally the outdoor pressure becomes stronger and pushes what little fumes the day old fire is still throwing, back through the stove and into my house. I've checked my chimney and flue, pretty darn clean, no blockages, chimney height is adequate. Cat appears to be functioning as it should. The only change I have made is that I'm not burning as good of quality wood as I was all winter, but I'm still producing 500+ degree fires, nor do I think that would matter 30 hours later. I'm just not sure why all of a sudden I'm having this issue. All I can logically think of is the change in seasons, warmer days and cooler nights and higher pressure causing the stove to lose a draft when it is finally burning out, however I didn't have this problem when I was burning in similar conditions this past fall. I know that I have a cold chimney and a moderately tight home, but it hasn't been an issue until now when the weather is becoming warmer. My dad said he has only had his CO detectors sound twice in the past 25 years due to the wood stove, but he has a masonry chimney that's central in the home. He is an experienced HVAC Tech and seems to also believe that the combination of my cold chimney and more pressure due to the season is the culprit. If anyone has had similar issues, I could use any advice or possible solutions you had luck with. Also, If you think there's a different cause to the issue, please share!

Thank you!

 

[weatherguy]

Warmer weather equals less draft but some basement installs have this problem. Couple of experienced guys will come along and give you more details.

 

[Woody Stover]

Your house itself may have a stack effect, with warm air escaping the envelope upstairs and drawing air down the chimney and through the stove, which is below the neutral pressure plane of the house. You can try to limit the amount of warm air going to the attic by air-sealing the attic access and ceiling light fixtures in the floor of the attic.

 

[moresnow]

If you get a chance post a few pics of your stove and its location/setup in the basement. Any chance you have a walk out basement?The more details you can provide the better.

Read the article I have linked here. http://wood-stove.org/warnock-hersey-wood-stove.html.

Many times you will have a tag on the back of the stove identifying the make/model. Post a pic of the tag if possible.

 

[jetsam]

I would want to move the stove upstairs and add an outside air kit (and possibly some flue height since you just took 8' off by moving the stove).

This actually doesn't directly address the draft reversal, though the OAK may help. Is the flue insulated?

What kind of stove is it? Warnock-Hersey is not a stove manufacturer. If it's an old stove or needs work, might be a good time to upgrade.

As a stopgap measure, try shutting down the air all the way after the fire is done. When your draft does reverse, less stove exhaust should come in this way.

 

[ShawnLiNY]

Kitchen or bathroom ventilation can cause this as well as clothes dryer . Leave a basement window cracked slightly to prevent negative pressure

 

[SouthcountyRI]

Moresnow, thank you for the response. Haven’t thought about the issue since last spring until last night when I woke up to CO detector sounding about 55 hours after I last threw a log on it and let it burn out. Yes, it is a walk in basement, double wall flue. The picture I attached is the day I did the flue, no the cardboard is not still right next to the stove. From there is goes through the sheet metal thimble made to go through the old window and up the gable end of the house, outside the house, inside a vinyl sided “chimney”. Will get more pictures of the set up after work today.

 

[jatoxico]

I think you're right about why this happens, its not uncommon. A smoldering bed of coals that's not putting enough heat into the chimney will dump CO into the house if the draft collapses. What I can't quite understand is why it would happen more than 2 days later.

Was there still an active bed of coals at the time?

 

[SouthcountyRI]

Jatoxico, yes it will hold a bed of coals that’s still making CO for more than 24 hours, in last nights case more than two days later it finally loses the draft. depends on how hot and how many days I keep the fire going, last fire was about 5-6 days. Also ozone pressure seems to have an affect obviously, seems to happen more during overcast, high pressure days/nights.

 

[jatoxico]

Sounds like you're on the edge. Some folks have a constant persistent problem with their basement install. Any sealing you can do in the attic will help. Also. how long is the overall stack? IDK if additional length can help overcome pressure issue once its cold but another couple feet may do the trick.

 

[SouthcountyRI]

Picture of the sticker on the side

 

[Woody Stover]

Energy King, CRD Mfg, Chippewa Falls, up 'air in good ol' WI.