Heatilator MF36 fireplace and chimney cap/flue questions

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Brawndo71

New Member
Nov 21, 2021
24
MO
Hello. I have a Heatilator MF36 fireplace with a TB48 metal chimney surround. The old top seems to let in some rain water, not a very good design, or pleasant to look at. I had to replace the interior refractory panels and hearth due to age and water. I was wanting a stainless steel chase cap installed with a new air cooled cap, but the contractor says they need to extend the current liner and flue above the chase cap for proper air cooling. Makes perfect sense for how the system works, but for code they need the factory piping, with 8" inner and 13" outer diameter liner. According to Heatilator these parts, Part AC512 (12") are no longer made. The old cap had the liner terminate below the surround, and a single pipe inserted into that which led to the termination cap. Based on this, the extension pipe was letting some heat up the seam, as its not perfectly concentric within the 8" chimney pipe. Bad design, considering this is exposed to the attic below the cap.

Is there any way to identify what these fitting types are, get them from a third party or have them custom made? Or would the entire chimney flue system need replacing. Its not a very efficient fireplace circa 1983, and I will eventually replace with something more efficient in the next 5-10 years or so. But i would like to enjoy the fireplace now safely. Considering how bad the single wall pipe extension was, i'd say extending the 13" liner would be beneficial and protect the house better than how it was originally installed. This is what I envision it would look like completed, minus the siding of course. Or am I stuck using the old cap, and maybe just cleaning it up some? Is that current extension a fire risk?

20210501_115240.jpg 20210205_140942.jpg Chase-Cover-1.jpeg cap and pipe.jpg 20210205_140935.jpg Resized_20210211_194624.jpeg
 
Last edited:

Brawndo71

New Member
Nov 21, 2021
24
MO
I priced parts from the fine folks at Rockford Chimney Supply. A cap is ~$280, the chase cover is ~$270 and pipe is another $100. It would need to come up another 12" or so to allow the chase cover install with storm collar. Anyone have an idea if this is possible, how to mate a 13" pipe to what is there, or does the whole system have to go? I am reaching out to the manufacture directly, and to other chimney specialists. I am not alone in this situation. It's been done before.
 

Brawndo71

New Member
Nov 21, 2021
24
MO
Here is a closeup view of the flue pipe and liner fittings. I couldn't find anything online regarding the type it is. From an inspection three years ago they said the flue looked new and barely used. I replaced the blowers under the firebox last year. The old axial fans made a tremendous amount of noise. The tangential fans move way more air, and are almost whisper quiet. No problem hearing the tv while on at moderate speeds. No response back from Heatilator other than this part is listed no longer available.

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Brawndo71

New Member
Nov 21, 2021
24
MO
Anyone have an idea if this is doable? Rivet or screw in a 13" extension for proper air cooling, then put a new 8" extension pipe inside the flue as previous, and put a chase cover on with air cooled cap? I am not going to reassemble it like it was, looks dangerous. Or should i just convert this to gas and not worry about it again? It would be a waste to not use it this season, or ever again. If i eventually replace it with a new efficient zero clearance fireplace, the original hearth and brick facade will have to come out, no real access behind, and i don't think i could get a stove at this location. At least it would get a whole new liner at that point. This house was built in 1983.

20180901_193321 (2).jpg
 

john26

Minister of Fire
Oct 27, 2008
714
Wildwood MO
I will be honest with if it was me I would remove the old ZC and install a new hi efficiency ZC or maybe even a free standing stove before sinking any money in this. I have some experience with builders grade ZC's family members have them and the heat output and efficiency is pretty pathetic . I understand wanting to use it for aesthetics but most gas logs need vented and you still have the leakage problem I would not want the water in the flu or chase. Maybe possible use an ethanol burner?
BTW what part of MO are you in?
 

Brawndo71

New Member
Nov 21, 2021
24
MO
I am in Oakville currently. Though I have lived in Columbia and Springfield thru the years. I am from Saint Louis. I am not currently looking to heat my home with a fireplace, haven't quite graduated to that desire. It is a process. I enjoy some evening and weekend fires, though you have to attend to them every 30- 45 minutes or so. I enjoy poking the fire, throwing logs on, splitting a little wood. I've got some friends and relatives that have whole house furnaces or do use their fireplace in that capacity. I just am not there yet. I was planning on upgrading in maybe 5 years, there are a couple of major projects ahead of this one. It's much lower than that on the SO's list of projects.
Yes this fireplace is inefficient, but it will warm the house up. I rarely burnt it longer than 4-6 hours per burn last season. Granted I don't want to be wasteful either. It would cost me ~$800-$1000 to complete the top with chase cover, cap, etc. If I can't get the chimney completed, I'll have to leave it out of service til upgrade. I didn't like the single pipe extension it had, clearly heat was coming up the side near the seam as it wasn't perfectly concentric within the flue. Its why I would want to extend the air cooled liner out the chase cover. It is currently tarped over.

I spent maybe $500 to do the firebox myself last season. I haven't priced what it would take to install a whole new ZC or stove yet. I am guessing $6k-$9k. The high efficiency ZC fireplaces sound great though. Any recommendations on who does great work or a certain model to get?
 

john26

Minister of Fire
Oct 27, 2008
714
Wildwood MO
I am in Oakville currently. Though I have lived in Columbia and Springfield thru the years. I am from Saint Louis. I am not currently looking to heat my home with a fireplace, haven't quite graduated to that desire. It is a process. I enjoy some evening and weekend fires, though you have to attend to them every 30- 45 minutes or so. I enjoy poking the fire, throwing logs on, splitting a little wood. I've got some friends and relatives that have whole house furnaces or do use their fireplace in that capacity. I just am not there yet. I was planning on upgrading in maybe 5 years, there are a couple of major projects ahead of this one. It's much lower than that on the SO's list of projects.
Yes this fireplace is inefficient, but it will warm the house up. I rarely burnt it longer than 4-6 hours per burn last season. Granted I don't want to be wasteful either. It would cost me ~$800-$1000 to complete the top with chase cover, cap, etc. If I can't get the chimney completed, I'll have to leave it out of service til upgrade. I didn't like the single pipe extension it had, clearly heat was coming up the side near the seam as it wasn't perfectly concentric within the flue. Its why I would want to extend the air cooled liner out the chase cover. It is currently tarped over.

I spent maybe $500 to do the firebox myself last season. I haven't priced what it would take to install a whole new ZC or stove yet. I am guessing $6k-$9k. The high efficiency ZC fireplaces sound great though. Any recommendations on who does great work or a certain mo
I am in Oakville currently. Though I have lived in Columbia and Springfield thru the years. I am from Saint Louis. I am not currently looking to heat my home with a fireplace, haven't quite graduated to that desire. It is a process. I enjoy some evening and weekend fires, though you have to attend to them every 30- 45 minutes or so. I enjoy poking the fire, throwing logs on, splitting a little wood. I've got some friends and relatives that have whole house furnaces or do use their fireplace in that capacity. I just am not there yet. I was planning on upgrading in maybe 5 years, there are a couple of major projects ahead of this one. It's much lower than that on the SO's list of projects.
Yes this fireplace is inefficient, but it will warm the house up. I rarely burnt it longer than 4-6 hours per burn last season. Granted I don't want to be wasteful either. It would cost me ~$800-$1000 to complete the top with chase cover, cap, etc. If I can't get the chimney completed, I'll have to leave it out of service til upgrade. I didn't like the single pipe extension it had, clearly heat was coming up the side near the seam as it wasn't perfectly concentric within the flue. Its why I would want to extend the air cooled liner out the chase cover. It is currently tarped over.

I spent maybe $500 to do the firebox myself last season. I haven't priced what it would take to install a whole new ZC or stove yet. I am guessing $6k-$9k. The high efficiency ZC fireplaces sound great though. Any recommendations on who does great work or a certain model to get?

I am in the St Louis area living in Wildwood now but from Maryland heights. I do no over a few shops in St Louis although I have never hired any to do work. I have bought stuff on several occasions from Victorian sales in Fenton. They seem pretty knowledgeable and have a service department they may have an idea for your current situation. They also sell Napoleon and Valcourt. Valcourt has a few nice budget friendly ZC I have looked at them see well built but I don't have any experience with them. There is another shop in O'Fallon called The Madd Hatter I talked to them once looking for chimney parts seemed like the focused mostly on chimney and fireplace maintenance also very knowledgeable. As far as buying a new ZC if it was me I would be a pacific energy. I am very impressed with there products and quality. The Valcourt and Osborn would be a second choice. The big advantages of the PE is the firebox size and square shape with North South loading its efficiency and proven air wash system. I like the looks of the Valcourt but the firebox size and shape is less than desirable for me but I do heat with wood usually 3-4 cords a year. As far as your existing chimney maybe you could get a sheet metal shop to fabricate a cap?
 

Brawndo71

New Member
Nov 21, 2021
24
MO
Thanks. I have gotten supplies from CBennett in Ofallon, MO. They have a bunch of fireplaces too. Guess i need to call around to a couple of the other shops. Been trying to work with Forshaw as they are local Heatilator dealer. The issue is the code which says have to use same pipe style/vendor to connect. A local contractor won't work on it otherwise. Understandable. But the pipe is obsolete, and they have given me no option for an adapter, or how to replace the whole pipe, which seems extreme. But since the previous setup didn't even use that style pipe for the extension, and left it open to the attic below, I would say the extension of the 13" air-cooled liner is a very minor issue. It needs to come up ~12"-16". The original chimney install looked like a fire hazard to me, that extension pipe causes turbulence since it isn't perfectly concentric, and its open to the attic. A liner extension would guarantee anything ever possibly escaping that extension pipe would stay within the air-cooled liner.

I probably burn half a cord max a season right now., there is a full face cord on my rack right now. This isn't a run full time fireplace anyways. I do have a brand new gas furnace. I had to wait to repair the firebox last year, losing time. I did notice it took a load off the furnace last season when I did burn the fireplace. I will definitely replace with high efficiency once the time is right, maybe 5 years. Is $200/year worth it the question for those 5 years.
 

Brawndo71

New Member
Nov 21, 2021
24
MO
As little heat as this fireplace gives out, I am just going to leave it unused until I upgrade to a high efficiency ZC. Too bad no ZC fireplace qualifies for the Biomass 26% tax credit, which is only good thru 2022. I only see ~72% HHV for a fireplace. I like the look of a fireplace instead of a stove. The Astria models look pretty good, there is a dealer in town. Else it is Napoleon, Kozy Heat and Heatilator. I see no Pacific Energy dealers in the midwest. The room where the fireplace is measures 12'x21', house is ~2100 sq ft, with a 4-season room right next to the fireplace. It has a PTAC with heat pump, not good on the cold days. I might be limited to size based on the corner configuration. Unless it gets completely reworked.

Spending on more insulation for the attic instead of this old unit. Been working on the attic for a year, ventilating soffits and bathroom exhaust fans.
 

john26

Minister of Fire
Oct 27, 2008
714
Wildwood MO
There are 2 ZC's that qualify for 26% tax credit they are the same unit under different names
There are 3 Pacific Energy Dealers with in 100 miles of STL


Wiegmann Woodworking & Fireplace, Inc​

Distance: 54.06 mi
105 Sugar Creek Lane
62215 Damiansville
IL US
Phone: (618) 248-1300
Directions Call

Best Clean Fireplace Shoppe​

Distance: 57.79 mi
5429 Highway 32
63640 Farmington
MO US
Phone: (573) 756-8157
Website: http://www.bestcleanplus.com
Directions Call Website

Best Fire Inc.​

Distance: 87.61 mi
3518 North Ten Mile Drive
65109 Jefferson City
MO US
Phone: (573) 893-2525
 
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Brawndo71

New Member
Nov 21, 2021
24
MO
Thanks. I'll look into these dealers. Wiegmann has almost every manufacturer available. That Montecito Estate is more heat than i need. Even a lot of the stoves don't meet the 75% HHV, unless they are pellet or catalytic. Only 40% of those listed in the EPA database meet it. I think the 75% HHV threshhold is quite aggressive, if they are trying to weed out all the old units like I have. Maybe 70% would have been a better target.
 

john26

Minister of Fire
Oct 27, 2008
714
Wildwood MO
The Montecito Estate is a cat stove. I think you are confusing efficiency and heat output, the Montecito is able to be turned down 11,500 some some btu's and 40,000 on high end. That is lower than a lot of tube stoves. There are a few discrepancies with the stove for one the epa data base says 75% and the manual says 70%. The cuft rating is 4.0 in the manual and 2.8 on the epa rating, 2.8, I know the epa rating is usually less but that seems like a lot. The major draw back on the Montecito is the MSRP price is over 11K.
 

Brawndo71

New Member
Nov 21, 2021
24
MO
I have been looking at fireplaces according to my dimensions, since this is a corner installation. I drew a quick sketch. The bigger ZC and some manufacturers fireplaces just won't fit in the space according to the manual. The PE models don't fit, they need 94". The Osburn/Valcourt models need 79". Some other models need 89". Maybe those are doable. The current firebox shell is smaller, these newer ZC high eff are pretty big.
I am still researching. Need to put the models that fit in a spreadsheet. Thanks for your input. I don't think I would be running this 24/7, how safe is that? I would worry too much while at work, but burning from when I get home from work til the morning seems reasonable. So maybe 12 hours a day during the week. Or can these run low heat during the day?

20211214_085642.jpg
 

john26

Minister of Fire
Oct 27, 2008
714
Wildwood MO
I typically run my inserts on low pretty much all the time after getting the fire going. I leave the inserts unattended and burn 24/7 my wife is in and out through the day but I would feel safe with no one there. Victorian sales in Fenton sells Valcourt prices seem decent but it has been a year since I was in there.