Please critique my insert plan (a.k.a. follow up 2 on my stinky flue)

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StinkyFlueStu

Member
Apr 28, 2016
32
Missouri
Hi everyone. I've posted a couple of threads previously regarding the horribly stinky flue in our house. See previous here and here. After reading all the advice, plus finally finding a company here I think I can trust, we have a game plan. I'm hoping the experts here can review what we're going to do and give feedback and constructive criticism, point out anything we're forgetting, etc.

First, I'll describe what we're planning. I'll post a brief recap of everything that's happened below that, but the short version is that folks on the past threads agreed that we have a dirty flue, moisture in the flue, and negative pressure inside.

So, here's the planned work:

  1. Clean the flue
    • The new crew we're working with, which seems much more professional than the past 4, agreed with hearth.com comments that we have "stage 3" creosote.
    • Before anything else, they're going to clean it with chains to ensure a squeaky clean install.
  2. Install a 6" stainless steel liner (insulated)
  3. Blocking plates at the top of the chimney and at the bottom
  4. Install a CI2600 fireplace insert
    • I've read almost the full CI2600 thread, still working through the last few pages.
    • This insert is picked because, among those offered by the company we're going with, it has the look we want for the lowest price, plus it seems like it's pretty well liked now that the kinks are worked out.
    • Options we're choosing include:
      • Cat monitor/thermometer
      • Fresh air intake (they recommended this due to the weatherization work we've had done)
      • Blower
  5. Cleaning out and bricking over the ash dump
  6. Bricking up the existing fresh air intake
  7. Installing a junction box inside the fireplace so the plug for the CI2600 blower doesn't hang out the front of the fireplace
  8. Install new stainless steel chimney chase cover
  9. The quote for all of this is approximately $6,800 all in (cost of just the insert is about $2,700, the rest is materials for the liner and chase cover, labor, other materials, etc.), so also appreciate any feedback on that.
EDIT: Now they are saying that they were wrong, and the CI2600 doesn't have an outside air kit. And, even though they first said the outside air kit was necessary because all our weatherization work would make it difficult for the insert to get air from inside the house, now they're saying we don't need it after all... When I look through the CI2600 megathread, I see multiple people saying there is an outside air kit, so I don't know. I guess maybe I need to call Regency directly?
When they came out, they confirmed we had stage 3 creosote despite protestations of other sweeps (which conforms with what people on this site were telling us), they confirmed that our chimney is NOT too short (a couple other companies had said it is), and they confirmed our flashing is fine. Oh, and they took pics of the secondary flue. It looks like it was literally never used. So, they don't want to do anything with it.

We also talked about a special "wind proof" flue cap, but they said with our chimney being high enough, and far enough away from other tall items, that there shouldn't be such extreme down pressures that it would justify adding the cost. They said the closed system itself should be enough to deal with any wind that might happen to enter the chimney. I still wonder if it isn't worth it to just add it anyway, but I guess we could always throw it on later if necessary.


Some other facts about the house:

ranch style with a walkout basement, located at the top of a hill in southern Missouri (very hot and humid right now, winters can be mild or very cold and very wet or very dry), backs up to a forest. House faces north west, chimney is on the back, fireplace is in living room on main level.

The fireplace has a metal lining inside it. The team says they'll have to saw off "most of the top and back" of the metal lining, but they said that was normal. The fireplace did have built in blower with vents above and to the side of the fireplace. They say they're going to fill those cavities with insulation and "black out" the spaces between the bricks that acted as vents. They're also going to use the line that powered the original blower motors to feed a junction box that they then use to power the new blower motor.

Now a summary of the history, for context.

Honestly, I'd recommend at least reading my initial post on both threads. Here are the basics, though. A year ago we bought a house, had the fireplace flue inspected, fixed a crack in the mortar chimney chase cover, removed a retro-fitted gas insert from the originally woodburning fireplace, and sprayed "professional" water repellent onto the bricks outside. After a season of burning wood that was supposedly seasoned, but soaking wet due to being stored outside during a winter that never stopped raining, we immediately had our flue cleaned when burning stopped in January. We were concerned the flue still wasn't very clean, but the owner came out and swore it was fine. We started having occasional smell issues, so we plugged the bottom of the flue with a homemade "balloon" (insulation inside trash bags) and sealed the top with aluminum foil (dumb, I know). In February, we had weatherization work done on the house, such as caulking around doors and windows, more insulation in attic, etc. They also installed an exhaust fan that they claimed was required by law when weatherization work is done to "prevent bad air build up inside the house." It's always on, and they have subsequently claimed it's such low pressure that it couldn't possible be affecting the smell (and we already had some odor issues before it was installed, plus the big issues didn't start until long after it was installed, and we don't see any difference when turning it off or on). We also have a radon exhaust under the foundation, but again, that was running long before the problems started, and we see no difference when turning it on or off.

Anyway, in April, when the weather really turned to full time hot and humid, the house was flooded with thick, nasty, humid stink. We immediately had several sweeps out, and they all gave conflicting advice. Based on the few points where they did agree, plus advice from this website, we surmised that we had humid air getting in, despite covering the flue with foil, and it compounded to the point that it was so thick and heavy it was pushing past the balloon at the bottom. We tried numerous things, and no combination of windows open/closed, appliances on/off, etc. made a difference. The only thing that helps is burning candles in the fireplace, and we often have to have many, many very large candles burning, depending on the heat and humidity of the outside weather.

Okay, I think that covers everything. It probably covers too much. Please tell me what else I can share that is helpful, and please tell me if there's anything else we should do to make sure we have the best possible chance of beating this thing.

I'm adding the pics from the last thread. I have some newer pics of the inside of the flues, but I don't have them on this PC yet. Working on it!
 

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Good plan except that I'm not ok with putting the outlet in the fireplace. The insert will throw off a lot of heat still around its outer jacket. That heat will be trapped in the fireplace making it hot in the space surrounding the insert. While I understand the aesthetic desire, this doesn't sound like a good plan for a long term safe wiring job. Contact Regency and see if they approve of this part of the plan. Also check electrical code.
 
Mount the outlet on the floor of the fireplace firebox. Maybe even where the old ash clean out is, then seal the rest around it. Even my Summit never gets hot under the insert. There is also high temp wiring available, such as the wiring for the blower motors.
 
Floor temp and clearance varies with the insert. Some insert mfgs. specifically warn agains running the cord under the insert. Not sure what Regency would say, so I suggest asking. They may say no go or no problem.
 
Floor temp and clearance varies with the insert. Some insert mfgs. specifically warn agains running the cord under the insert. Not sure what Regency would say, so I suggest asking. They may say no go or no problem.

I've seen so many setups like this that I didn't think it would be an issue. This crew sounded like they do it all the time, so I didn't think to question it. I'll ask them about it, and I'll also double check with Regency.
 
I have a new question:

They just sent me an email saying that there isn't even an outside air kit option for the CI2600. When I search Regency's site, and the PDFs they have, I don't see a mention of it. However, over on "the" CI2600 thread, I see several people saying it does have an outside air kit, so I'm confused.

I'm just concerned because when they thought there was an outside air kit option, they said we need to get it because the weatherization work will make it difficult for the insert to get combustible air from inside, but now that there isn't an option, all of a sudden they say it's fine to use inside air...

Any thoughts?
 
There is also an email contact form at the link provided.
 
If that insert is rated for use in mobile homes than it has an outside air inlet as that is required by code now days. The lack of a specific kit from the mfg doesn't mean it doesn't have one, in some cases it is a simple matter of a couple screws to remove a blocking plate.
 
I was curious and checked the manual - the drawings show some sort of removable cover on the side of the insert - if it's not provision for an outdoor air kit, I don't know what it is.

That said, I don't think most inserts are designed for outdoor air kits, because of the difficulty routing the air into most existing fireplaces and connecting to the insert.

When I had my insert installed, the installer recommended this for makeup air, installed on an outside wall as close as possible to the insert:
http://www.condar.com/ASV.html

For reasons I won't bother mentioning at the moment, I preferred a slightly different approach, and got an ok from the installer and the county inspector (mortgage company wanted all the i's dotted and t's crossed) to instead draw make up combustion air from my crawlspace, which is properly ventilated. I had a small space under the stairs that was walled in - I put a 4" duct through the floor in that space, a 90degree elbow, and a exhaust hood with the damper flaps facing inward to minimize warm air outflow when no fire is burning - one of these, I think:
http://www.homedepot.com/p/Everbilt-4-in-Louvered-Exhaust-Hood-HS4W-18HD/205046974

This simple vent setup is neatly out of sight behind a small register. It's 7-8 feet from the insert, near floor level, so I believe the cold air is at least somewhat preferentially drawn towards the insert, rather than circulating around the house - not quite as good as an O.A.K., but certainly better than neglecting weatherizing.

For wiring, depending what the structure around the fireplace is, perhaps you can drill through through the brick on the inside and put a junction box in the wall to the right of your fireplace there - it might need a large masonry bit, followed by a long spade bit to get through any studs.
 
I was curious and checked the manual - the drawings show some sort of removable cover on the side of the insert - if it's not provision for an outdoor air kit, I don't know what it is.

That said, I don't think most inserts are designed for outdoor air kits, because of the difficulty routing the air into most existing fireplaces and connecting to the insert.

When I had my insert installed, the installer recommended this for makeup air, installed on an outside wall as close as possible to the insert:
http://www.condar.com/ASV.html

For reasons I won't bother mentioning at the moment, I preferred a slightly different approach, and got an ok from the installer and the county inspector (mortgage company wanted all the i's dotted and t's crossed) to instead draw make up combustion air from my crawlspace, which is properly ventilated. I had a small space under the stairs that was walled in - I put a 4" duct through the floor in that space, a 90degree elbow, and a exhaust hood with the damper flaps facing inward to minimize warm air outflow when no fire is burning - one of these, I think:
http://www.homedepot.com/p/Everbilt-4-in-Louvered-Exhaust-Hood-HS4W-18HD/205046974

This simple vent setup is neatly out of sight behind a small register. It's 7-8 feet from the insert, near floor level, so I believe the cold air is at least somewhat preferentially drawn towards the insert, rather than circulating around the house - not quite as good as an O.A.K., but certainly better than neglecting weatherizing.

For wiring, depending what the structure around the fireplace is, perhaps you can drill through through the brick on the inside and put a junction box in the wall to the right of your fireplace there - it might need a large masonry bit, followed by a long spade bit to get through any studs.


The shop called Regency for me. They said that this unit "draws very, very little air," so it doesn't need an outside air kit. They pointed out the fact that if anything, people complain about it getting too much air, which is why they created the restriction plate mentioned in the CI2600 megathread. So, they think it's virtually impossible that I'll have draft problems despite my weatherization work.

They did say that in a worst case scenario, they could remove some plates on part of the insert that's inside the firebox and put a small hole through the back of the chimney to allow some more air in, but they said that's almost guaranteed not to be an issue.

Does this all sound kosher?

Also, I have a couple more questions about making sure I don't skip anything on the installation:

  1. People here and some of the sweeps said that one of the worst things I did was plug up both ends of the flue. They said this let the humidity build and build and build since there was no air flow. Well, now the installation plan everyone recommends includes a plate at the top of the flue, sealing around the liner, and backstop plate at the bottom of the flue, sealing around the bottom of the liner.
    • Why won't this create the same problem (building up a ton of humidity and moisture that eventually explodes through a tiny gap to stink up my house?
    • Should I take some measures to help prevent this? For example, I've heard of "brick vents" that are used for moisture control, or maybe even some simple weep holes just above level of the firebox?
  2. Should I have them pack insulation into the firebox around the insert?
    • Wouldn't this increase efficiency and reduce the chance of smell getting past the face plate and into the house?
  3. Is it normal for there to be nothing but empty space around the liner inside the flue?
    • I remember a thread on here once where the guy talked about pouring cement down around his liner, filling up the space in the flue, and I saw something like that on a YouTube video as well.
    • The shop I'm working with says they've only heard of something like that if you're NOT doing a metal liner and instead trying to basically re-line the flue with the cement.
    • Should I look into something like this, or even just blowing insulation into the flue around the liner? Again, wouldn't this increase efficiency and help prevent nasty air building up in the flue and escaping into the house?
  4. Regarding the outside air...
    • I do currently have an outside air vent in the bottom-front of the fireplace. The current plan is to seal it up and brick over it.
    • Should I instead have them leave it wide open to give air to the insert? Or would that just make the possibility of that hole sucking out all the heated air from inside the firebox and maybe even inside the house--or worse, somehow cause smokey air to escape into the inside of the house?
If it isn't obvious from these questions, I am both completely new to inserts and also incredibly paranoid due to the months of nightmarish stink we've been experiencing. Any help is welcome, even if it's just telling me to chill out. If this post alone justifies a new thread, let me know.

Thank you guys for everything.
 
#1 - Stage 3 creosote stinks. You are getting rid of it.
#2 - ask Regency if they approve and see if you have room behind the insert for this. If they are ok, go for it. If they say it will void the warranty, then no.
#3 - Yes
#4 - your call

Did Regency give blessings for the cord going under the stove to the outlet?
 
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#1 - Stage 3 creosote stinks. You are getting rid of it.
#2 - ask Regency if they approve and see if you have room behind the insert for this. If they are ok, go for it. If they say it will void the warranty, then no.
#3 - Yes
#4 - your call

Did Regency give blessings for the cord going under the stove to the outlet?

  1. There will still always be some amount of creosote though, right? You think there's no risk of humidity/moisture building up and causing more stink? Or just that with the cleaning+liner+blocking plates, the likelihood of stink getting in the house is small enough that brick vents would be overkill?
  2. Will do.
  3. Okay. Does the fact it's typical to leave it empty also mean it's a bad idea to fill in that space with insulation? Or just not worth it?
  4. Will discuss with Regency and the "team"
I have requested that the installers give me details into exactly how they plan to add the power. They said they'd be using the existing power that goes to the old blower that is already installed behind the bricks, but also mentioned a junction box. Once I get more details into exactly what they're doing, I'll discuss with Regency.

I have seen videos of insert installs where there is a literal outlet placed inside the firebox for the insert to plug into. I just assumed there must be some kind of high-temp equipment made for this. I mean, the cord from the insert is obviously able to withstand the heat, so I figured they could make the rest of the equipment heat resistant enough.

You're awesome for the diligent help. I'm so glad I found this site.
 
The risk will be greatly reduced but it's impossible to say, especially without being on site to inspect. That will be up to the pros. If the chimney brick and mortar are still sealing well then it should be ok. With an insulation wrap on the liner there is no need or worthwhile gain from pouring insulation around it.
 
The risk will be greatly reduced but it's impossible to say, especially without being on site to inspect. That will be up to the pros. If the chimney brick and mortar are still sealing well then it should be ok. With an insulation wrap on the liner there is no need or worthwhile gain from pouring insulation around it.

Sorry, which parts are you responding to in your first three sentences? I'm guessing the bit about brick vents, right?
 
  • You think there's no risk of humidity/moisture building up and causing more stink? Or just that with the cleaning+liner+blocking plates, the likelihood of stink getting in the house is small enough that brick vents would be overkill?
 

Okay, that's what I thought. Thanks.

By the way, if you guys have concerns about the electrical stuff, can you tell me what the standard approach is? Just have the cord coming out from under the backing plate and plugged in somewhere outside the firebox? The install company told me via email their plan involves having the junction box "inside the masonry, where heat won't be a concern," but I'm going to get some more details from them and ask Regency.
 
Small update: now the shop says that Regency has just recently added an outside air kit. So, we can do outside air without any jerry rigging.

Now I just have to figure out whether it's better to suck the air down the chimney (four inch pipe goes from insert, up through block off plate to suck air from cavity around liner, the plate at the top has a 1 inch air gap to allow air to be sucked down into the flue) or to get it straight out the back (cut 4" hole in back of firebox and pipe it in from there).

I think there are pros and cons of both. I had worried about the fact that the flue will be completely sealed off, since so many people said a large part of our problem was sealing both ends of the flue. Drawing air through the flue ensures the flue is not completely shut up on both ends. Plus, once a fire is going, the air coming into the insert will be warmed up already.

On the other hand, I also worry about more moisture/humidity getting down into the flue, and it seems like this air gap will increase the risk. Plus, it seems weird to suck air from right next to where the exhaust is coming out. Won't I be purposely sucking smoke down into the insert now (which could come out into the house)? And won't the air being fed into the insert now have a lower oxygen content, meaning a less efficient fire?

Thoughts?

I made a thread just about this topic, hoping to get some more visibility but also so that anyone with similar questions in the future has an easier time finding answers:

https://www.hearth.com/talk/threads...-hole-through-the-back-of-the-firebox.155558/
 
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Outside air means just that. I've never heard of outside air coming from the chimney cavity around the liner? Who suggested that? Can the outside air be routed through the ash dump?
 
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