Urgent Help Needed - Smoke leaking from pipe joins

[Gina]

Hello. I have a vermont casting encore with a cat. I have used wood stoves for cooking and heating for over 10 year in previous homes). It has been installed in my new (well very old victorian) house for 14 months. It sits in the LR and goes into the ceiling with one elbow join (I wanted to use the hole from the previous stove that was there). It then goes up through an upstairs bedroom straight, up into the attic (which is like a full third story) and then has one more elbow join to get it out of the roof. It was professionally installed. My wood was delivered last year from a reputable source. All hardwood. The stove functioned perfectly all winter last year. I had enough wood left over for this year so I stacked it on pallets correctly and it has had another year to season even more.

I clean the stove once a week including the cat (v. gently) according to my manual.

This fall when I started using the stove again everything worked perfectly. By working perfectly I mean that I get a fire started with kindling. Add some small logs. Add medium logs and wait a few hours for a coal bed. Then load in a couple of big logs through the top and engage the cat/ damper. Before I go to bed I un-engage the cat, add more wood to the coal bed, reengage it and sometimes turn the air down. In the morning I un-egange the cat, add small logs wait about an hour then load it up and engage the cat and leave for work. Using it this way means I don't ever have to kindle a fire in the morning or evening because of the coal bed. I only kindle a fire when I let it go out deliberately to clean it. So to me this is wonderful and I thought I was using the stove correctly.

On saturday we had temps of -20 degrees in the morning. When I woke it followed my normal procedure. Suddenly the stove started "burping" smoke through the top loading door, the front doors and all the chimney joins in the LR including where it enters the ceiling. I called the installer. They said to shut the stove down. I carried the smoldering wood outside and it took a long time to clear the house of smoke. On Tuesday they were able to send someone out. They felt the chimney pipe was obscured. He cleaned it from the bottom up (so not from the roof). he said there was barely any creosote build up at all. he couldn't get a fire to draw (using cardboard and small kindling). the smoke just pours out of the doors and the joins.

Then they said the back drafting and poor draw was likely a very cold chimney. The temp here now is 30 degrees. So 50 degrees warmer. I was told to start a very very hot fire and warm the chimney. Last night I did that. Smoke billowed from the doors and the joins. Closing the doors put the fire out. I kept the doors open and while it took an hour finally I could feel that the chimney was warm in the upstairs bedroom. The chimney pipe in the living room was almost too hot to touch.

But still with that hot hot fire, adding anything larger than two inches would give me smoke again. Engaging the cat - smoke. I was finally able to close the doors and not have smoke but I can't add any new wood that's not tiny tiny without getting smoke.

What is so odd to me is that the firebox clearly fills with smoke when I add wood. I can see it through the glass doors. Then it starts to leak out of the chimney joins. So this morning I checked that the damper and air flow system inside the stove was not blocking anything and I can put my hand up and into the chimney pipe. It's hard but my hand is small. So the opening from the firebox to the chimney is there. The smoke just won't go up the chimney. The installer has no good ideas for me yet.

I'm trying to attach pics. One from the initial installation. Then one of the spot where most of the smoke is coming out where it goes through the first story ceiling/ floor into bedroom. One of the stack. You can see the smoke damage on the joins that wasn't there on Friday night. There is no smoke leakage in the upper bedroom or attic. Those pipes are double walled I think is the term.

Any ideas or help would be appreciated. It is my primary source of heat and the house is in the 40's.

 

[kennyp2339]

Off the cuff I would say either clogged or really restricted chimney cap..i would confirm that by going outside and looking at the cap with binoculars, even though he did a bottom to top cleaning, he might have missed the cap.
Secondly with the stove is the damper working properly, was the cat re-installed in the right direction?

 

[Gina]

Thank you. I'll take any suggestions! I called the installer and asked them if the person checked the cap and if not that I wanted it checked asap. I know I have one because I was having birds come down constantly (really mean birds who pecked me when I rescued them - starlings I think) and so I told them to put up a mesh shield or whatever stops birds.

The CAT has a direction? It looks the same on every side to me. Do you mean maybe I have it in upside down or else back to front? How can I tell. The reason I am so interested in this is because when I cleaned out the stove after the Saturday incident, the CAT "area" above and below the honeycomb thing was filled with quite large bits. Usually I have one or two clogged honey combs. This was alot. Now should it matter if the damper is not engaged? But still it was unusual.

 

[branchburner]

Welcome to the forums. It sounds like you have already disproven the cold chimney theory. Because the problem started all of a sudden, it almost seems like something sudden was the cause of it, like a bird or a big hunk of ice or creosote dislodging from the cap and getting stuck in the very top of the chimney. But is seems as likely that the sudden lack of draft is coming from the stove end of the system, meaning that for some reason no air is entering the stove to feed the primary and secondary air supplies.

It sounds like the fire burns when you have the stove door cracked, and goes out when closed. Is this correct? That would mean you have an air supply from the open door, but possibly no air when closed. Is this stove installed with an OAK (outside air), that might be obstructed? Did the dealer inspect the stove at all to see if there could be a problem with air intake? Do you see any difference in the fire when attempting to adjust your air control?

 

[jharkin]

Agree with others - you have a clog in the system somewhere - the cap is the likely candidate. Your 3 story interior flue is WAAY above the minimum spec so you should have tremendously strong draft in anything but the mildest weather. (the cold flue downdraft problems usually manifest with short stacks, exterior pipes and basement installs - none of which apply to you)

In fact most people with a VC catalytic stove on a flue like that often have trouble controlling the stove and avoiding overfire.


Your wood sounds good, but you operating procedure needs some adjusting. The cat should not need to be cleaned weekly... even once a season it shouldn't take more than a light brush off if its been operating well. Seeing clogged cells in the cat on a weekly basis means you are burning too cold and the catalyst is not actually lighting off to burn the smoke. The fact that you burn an entire load down without engaging it is probably contributing to this, AND gunking up your flue badly with creosote (hence the clogged cap). Reloading and them immediately closing the damper without allowing it to heat is equally bad and can stall the cat.

On every load, even a cold start- you should let the fire burn wide open HOT and then close the damper/bypass and engage the cat as soon as the stove temperature is high enough for it to light off. A catalyst temperature probe is a great tool to tell you when its operating properly but if you don't have that just walk outside - if you see billowing gray smoke after the damper has been closed 5-10 minutes the cat isn't working and you need to reopen the damper and heat up the fire some more.

Read https://www.hearth.com/talk/threads/2016-2017-vc-owners-thread.156768/page-3#post-2131197

Don't worry about installing the cat wrong , they aren't directional and can go in either way. If the encore is a 2550 model however note that the refractory piece that holds the cat in is directional - it has two lips/edges on it - the side facing the cat has the smaller lip oriented on the bottom to hold the cat up, and the side facing into the stove has the larger lip on the top over the passages in the lower fireback that admit secondary air.

 

[Gina]

Thank you. I'm definitely installing the refractory piece correctly. I will read this thread and adjust my operation. I really appreciate it.

 

[Gina]

It sounds like you have already disproven the cold chimney theory. YES. I really feel I have.

Because the problem started all of a sudden, it almost seems like something sudden was the cause of it, like a bird or a big hunk of ice or creosote dislodging from the cap and getting stuck in the very top of the chimney. STILL waiting for a call back to find out if the cap was inspected. I don't have a ladder or an inclination to go up there. I can however get binoculars. I did zoom in with the phone but the photo is too blurry.

But is seems as likely that the sudden lack of draft is coming from the stove end of the system, meaning that for some reason no air is entering the stove to feed the primary and secondary air supplies. RIGHT. I feel like it could be inside the stove.

It sounds like the fire burns when you have the stove door cracked, and goes out when closed. Is this correct? That would mean you have an air supply from the open door, but possibly no air when closed. Is this stove installed with an OAK (outside air), that might be obstructed? Did the dealer inspect the stove at all to see if there could be a problem with air intake? Do you see any difference in the fire when attempting to adjust your air control?[/QUOTE]

The only way to get the fire to burn was to have both doors wide open. This was during the effort to warm the chimney. Closing the doors sent the flames down immediately. The stove does not have an OAK. I don't know that I toggled the air control while I had the doors open with the big fire. I was battling the smoke. I will get another message to the dealer asking if the person who cleaned the chimney (and said there really wasn't much to clean) also inspected the air intake. Is this something I could look at myself. I don't have a vacuum. Should I go buy one and vacuum the stove out? Or compressed air that you clean computer keyboards with?

Can I seal up the joins?

 

[Gina]

On every load, even a cold start- you should let the fire burn wide open HOT and then close the damper/bypass and engage the cat as soon as the stove temperature is high enough for it to light off. A catalyst temperature probe is a great tool to tell you when its operating properly.

Sounds like I need a CAT probe and a stove temperature gauge. This was not told to me when I bought it but from reading the forums a lot of you use temp guages.

 

[branchburner]

Seems that if the stove doors are wide open and smoke is not pouring out, but pours out of seams when doors are closed, that closing the doors is killing the draft of the system. That is of course the opposite of normal, and implies that closing doors removes the ability for air to flow through the system and reduces draft rather than increasing it. If you are not getting much smoke spillage with doors open, it seems less likely that the problem is in the venting or cap, and more likely in the stove's air intake or distrubution and supply to the firebox.

 

[jharkin]

The only way to get the fire to burn was to have both doors wide open. This was during the effort to warm the chimney. Closing the doors sent the flames down immediately. The stove does not have an OAK. I don't know that I toggled the air control while I had the doors open with the big fire. I was battling the smoke. I will get another message to the dealer asking if the person who cleaned the chimney (and said there really wasn't much to clean) also inspected the air intake. Is this something I could look at myself. I don't have a vacuum. Should I go buy one and vacuum the stove out? Or compressed air that you clean computer keyboards with?

Can I seal up the joins?

Should be no need to seal any stove pipe joints. If the flue is clear and you have an obstruction in the stoves air intake, closing the doors should cause the flames to smother and it to start sucking room air IN to the stove joints due to the chimney draw. Smoke coming out of the joints means its not able to escape up the flue.

I would still suspect the cap.

There is also a chance things are clogged internally. One quick check is to look at the primary air inlet - its a small door on the center back of the stove all the way at the bottom behind the ash pan. With the stove cold and the air control closed take a look back there- you should see the shutter completely closed. Now push the control to open and you should see the shutter rotate inward. If the stove is cold you can feel in there with your fingers for debris.

If that doesn't turn up any problems and the cap is clean then there may be obstructions deeper in the stove. Rare but not impossible. If you are adventurous and have a decent set of tools I can talk you though how to take out the interior panels to check.

On every load, even a cold start- you should let the fire burn wide open HOT and then close the damper/bypass and engage the cat as soon as the stove temperature is high enough for it to light off. A catalyst temperature probe is a great tool to tell you when its operating properly.

Sounds like I need a CAT probe and a stove temperature gauge. This was not told to me when I bought it but from reading the forums a lot of you use temp guages.

Yes, the VC factory manual covers the use of a thermometer on the stove top but not much else, and their operation instructions are very simiplified. The procedures I laid out where put together by a half dozen or so of us frustrated VC owners here on the forum via trial and error over the years. You are very much welcome to come over to the VC discussion thread and join in and we will try and help you through this - we have all been there.



BTW - can you confirm what model number your Encore is? there where many catalytic models over the years - 0028, 2140, 2910, 2055, 2040 2n1 (current)

 

[begreen]

Smoke should not pour out of the stove if the bypass is open. If it does, there is an obstruction in the chimney, reversal of draft or a puffback has occurred. A puffback is a small explosion of trapped wood gases in the firebox that suddenly ignite. Typically this happens with poorly seasoned wood and the doors being closed too soon before the wood is burning sufficiently. Closing the doors snuffs out the flame, but the wood is hot enough to continue to smolder. Wood gases build up, then a small flame appears and poof the gases ignite.

After verifying that there is no obstruction in the chimney and the cap is clear I would try leaving the door ajar for a bit longer and uses some smaller splits to start the fire. Criss-cross the wood so that air can easily get between the splits and kindling. Once the fire is burning vigorously be sure the air damper (thermostat control) is wide open before closing the door. Wait for the stove to warm up before closing the bypass.

 

[Squisher]

If I clean from the bottom up and I'm not going to be going up top at all then when my cleaning whip is through to the cap, that is when I go outside and visually confirm with high powered binoculars. Sometimes to clean the cap effectively I use my cleaning whip(rotary style cleaning) that is sized for 6" pipe to clean, and then I send up a larger whip which will expand more once out the top and clean the cap more effectively.

Were you home when it was cleaned? Did the sweep visually confirm his cleaning whip/brush was through to the top(go outside and look). Is your roof hard to access this time of year because if not they should definetly have gone up top to confirm there work, espescially with those offsets inside which would hamper a visual inspection from below.

Also do check everything over as best you can yourself as far as how your stove is set up. I recleaned a chimney recently that had been done at the beginning of the season by someone else and had clogged in less than two months. I suspected the cap, wood. But in the end I discovered the sweep had put the stove back together wrong and completely blocked off the primary air by reversing one simple piece inside(primary air dispersal plate on a PE was flipped 180 and completely blocking all primary air).

 

[Squisher]

I've also seen first hand where a chimney has been cleaned with a brush(not rotary) from below and it pushed all the build up into the cap completely blocking it. A homeowner did it and then called me out. Their chimney was terrible access so I whipped it with my rotary from below and easily cleared the cap, confirmed it visually and with a video. And the homeowner had done a decent job, the chimney was spotless except for the cap.

Visually confirming by accessing or videoing is a big part of sweeping IMO. I aim to leave each job knowing there is no issue because I have visually confirmed that there isn't any fuel(creosote) left in the system that could cause any problems.

 

[Gina]

This has all been so helpful. I'm hoping it is the cap although I will check the primary air inlet too. They squeezed me in and it was almost 5pm here so getting pretty dark. I don't see how he could have visually inspected the cap unless he went on the roof. He cleaned the chimney pipe by disconnecting it above the stove and went up from there. So I don't think he could have put something back wrong inside the stove. I don't think my roof is hard to access. It is high. The company had no problem going up there for the installation.

I need them to talk to their technician about what he did to ensure that cap was clean and I want them back there in daylight while I'm present. I think that needs to be my next step.

 

[Gina]

BTW - can you confirm what model number your Encore is? there where many catalytic models over the years - 0028, 2140, 2910, 2055, 2040 2n1 (current)[/QUOTE]

The 2040 but in biscuit.

 

[Gina]

Seems that if the stove doors are wide open and smoke is not pouring out, but pours out of seams when doors are closed, that closing the doors is killing the draft of the system. That is of course the opposite of normal, and implies that closing doors removes the ability for air to flow through the system and reduces draft rather than increasing it. If you are not getting much smoke spillage with doors open, it seems less likely that the problem is in the venting or cap, and more likely in the stove's air intake or distrubution and supply to the firebox.

Welll... it took over an hour with the doors open and a blazing hot fire with 1 inch kindling sticks to get the smoke to stop rolling out of the doors... If I tried to add a larger piece, smoke came out of the open doors.

But I'm going to check the air intake as best I can...

 

[maple1]

If you had a cap installed to keep birds out, that should mean it has a mesh or screen on it. Which are terrible for blocking up with creosote. My bets are on that.

If that does turn out to be the case, I would also give the company who supposedly cleaned it & gave an all-clear an earful - that could be a dangerous situation.

 

[Gina]

They can come out and go up on the roof on Friday. I won't use the stove until then. They said they didn't recommend the mesh when they installed it. On the other hand if a sweep and cleaned the stove pipe then the mesh and cap should have been looked at as part of the cleaning right?. I can tell them to remove the mesh. The bird problem was significant. One to three a week. If I went away for a weekend in the summer then a few dead bodies when I got back. If mesh is not the answer, is there another option?

 

[fire_man]

Have you looked at the cap while you had smoke spilling in the house? You might be able to confirm a clogged cap by witnessing how the smoke behaves as it leaves the cap.

I'd be surprised if the sweep did not inspect the cap when he cleaned the flue, especially since he was there for a problem.

 

[kennyp2339]

I know I added my thoughts to a clogged cap but I'm thinking of a video I saw years back (like 5 yrs ago) that a guy had a sudden draft issue and he traced it back to the back of the stoves refractory plates being clogged up, nothing in his user manual suggested that area would need to be cleaned, never the less could develop a problem, I remember the video showed a full creosote clog between the plates, shutting down the draft and killing the stoves function.

*found it, different stove than the OP's but still a good read,

http://woodchuckcanuck.com/2011/12/18/our-harman-fireplace-wood-stove-goes-boom/

 

[fire_man]

I'm not sure how that would explain smoke from the pipe joints. Seems like that would make it hard to get a fire going and smoke spilling out the door. Still good to keep in mind, though.

 

[jharkin]

A refractory chamber full of creosote would only cause a problem when the bypass damper was closed. The OP is having the issue on a fresh start.

Also, having that much buildup in the chamber of a catalytic stove would mean the catalyst has never been active. Get it up to temp once and the searing 1100-1600 degree heat of the cat burns it all out. A properly operating catalytic VC may will be caked with creosote inside the firebox, and sometimes the flue isn't all that great - but the cat chamber is nearly always clean as a whistle unless its failed completely.

(note the Harmon is a non-cat, its reburn system is finicky like the VC everburn's)




I still suspect cap.

 

[edthesweep]

They can come out and go up on the roof on Friday. I won't use the stove until then. They said they didn't recommend the mesh when they installed it. On the other hand if a sweep and cleaned the stove pipe then the mesh and cap should have been looked at as part of the cleaning right?. I can tell them to remove the mesh. The bird problem was significant. One to three a week. If I went away for a weekend in the summer then a few dead bodies when I got back. If mesh is not the answer, is there another option?

I never use anything except one inch stainless steel mesh/cloth (aka screening) (stainless steel wire welded into one inch squares) screen a wood burning flue cap - this really minimizes the chance for it to clog in between sweeps, however it is absolutely still possible and absolutely still needs to be cleaned with every sweep. I do 90% of my sweeps from the bottom but i go to the top to inspect the chimney and flue and clean the cap 100% of the time. A few times over my lifetime a very small bird or bat has gotten in through this screening but I wouldn’t go smaller or larger - it is a perfect combo of effectiveness yet non clogging. If the sweep didn’t go to the top to do this , ESPECIALLY AFTER HIS COMPANY INSTALLED IT AND WAS THERE FOR A SMOKE ISSUE HE IS VERY INCOMPETENT AND I WOULD DEMAND THE SCREEN CLEANED THEN DEMAND REFUND

 

[Squisher]

Interesting Ed. I clean mostly from the bottom too. I work solo so I prefer to keep an eye on what's happening inside as I clean so I can pace my clean so the vacuum keeps up and no soot escapes.

While I endeavour to get topside on everyone if the access is terrible and I can clearly see the cap or there is no cap (common in these parts on a clay lined masonry chimney) than sometimes I won't, as I charge more if it's tough access and if I don't feel I really need to get up there then I'll skip it. Or sometimes I'll run a video recording flashlight I have that snaps onto my rods up to have a quick check. It's super fast to deploy so for me sometimes I feel it's a better option than going topside.

 

[Gina]

I honestly didn't think to do something so simple. Both times the fire has been on (Saturday and then Tuesday) the smoke inside the house was my primary concern. I should have thought to check the chimney. Kind of like when tech support says is it plugged in. I wish I knew how much smoke if any there was and what color.