Problems with Avalon Pendleton Insert

[mickydean]

Hi gang...bought the Avalon Pendleton insert used a year and a half ago for supplemental heating...installed (professionally) in a vintage 1950s "Heatorlator" metal firebox...6 ft flexible stainless pipe from stove meets flue in chimney (rebuilt in the 1950s)...insulated around the original hearth opening on top of the stove- on the sides, less than a quarter of an inch between the stove and the hearth opening is uninsulated and open.

room with the insert is 12'x16', uninsulated walls, one window and exterior door, below- uninsulated crawl space, above- uninsulated attic...(House is 1896 farm homestead Victorian- 1st floor front 3 rooms insulated and over unheated full basement, back 3 rooms- including one with insert- uninsulated and over crawl space).

Last year the stove was a disaster, failed to heat the room it was in much less the back part of the house...bought a blower and the output is better but fails to heat appropriately...the outside temp of the stove ranges from 350 to 450 depending on the wood used...in 25 degree nights the room will reach a maximum of 74 degrees averages around 68 (thermometer at eye level) but fails to heat any of the other rooms...in 15 degree nights (last week) the room reached a maximum of 64 degrees and hovered between 58 and 62 degrees...and the central heating system does kick on as the thermostat is in a different room in the middle of the house, so the room with the stove is getting help from the central heat system.

have no problem starting the stove, draft seems to be good, only slight smoke will enter the room if I open the door too quickly...I am very disappointed- I had visions of walking around in a tee shirt (at least in that room)...I had a friend who is a former engineer come take a look and he seems to be stumped...of course, insulation would be a plus (yet complicated) but the friend said that the room with a 400 degree stove should be toasty without insulation...the heat is going somewhere...any suggestions are greatly appreciated...thanks, micky

 

[begreen]

Welcome micky, I added some paragraph spacing to make more readable. Complete sentences are nice too .

How well seasoned was the wood burnt last year?

The stove is not the main issue here, lack of insulation and probably caulking is. You are currently trying to heat outdoors. Take care of that and the stove operation should improve a lot.

Regarding the stove, is it on an exterior chimney? Does it have a full liner and is there an block off plate installed below the damper? If not, that will improve it's output.

 

[webbie]

Question - is the 400 degree temp you mention on the single wall portion of the stove top?

If so, that is too low of a temperature - real decent heat starts at about 500-550 and the stove should be able to be brought up to 800+ on the single wall top (as far back as you can put the thermometer).

Do you have a tight sheet metal plate which seals off the fireplace - level with the lintel on a horizontal plane? Without this, a lot of heat will escape up the chimney.

I suspect not enough draft and a less than tight seal at the damper area.

 

[EddyKilowatt]

Webmaster -- I have a Pendleton but in freestanding form, and as near as I can tell there is no single wall portion of the firebox anywhere on the stove.

The front portion of the firebox wall has the air intake pre-heater channel wrapped around it, and right where that stops (maybe 4-5" back from the front of the stove), the outer sheetmetal warm air shroud begins and goes all the way (5 sides) around the firebox.

I have my Condar surface temp thermometer on the front face of the stove, in the corner just above the door latch -- this is also part of the air preheater channel. It is there so I can see it from my easy chair, but my recollection is that the readings are not hugely different on top of the stove. I'll be glad to do an A-B comparison if there's interest.

For my front-face thermometer location I would say that for this stove 400F is cool, 500F is warm, 600F is hot, and over 600F is what's-that-smell hot.

Micky, I don't fully understand your installation but I would tend to suspect as BeGreen does that a lot of your heat is getting up the chimney somehow.

I guess the first thing is to establish whether you are making the heat but it is not getting into the room, or you are not making the heat in the first place. Do you have any way to measure flue temperature at the stove outlet? That would be a good clue to how hot your fire really is. I use a Tel-Tru probe-and-dial type thermometer at the flue collar, and generally see 700-800F during a hot burn (the kind that will get the stove over 600F if it lasts for an hour).

I did find when I first started using this stove that it was reluctant to burn with splits laid on the floor of the firebox per the manual... the burn was hotter, cleaner, and more reliable whenever the splits happened to be sitting up on a couple of short fore-aft sticks. I eventually wound up with a couple small pieces of firebrick that permanently act like "sticks" and let air circulate all the way to the back of the firebox.

I heat an uninsulated 1000 sq ft California Ranch (with single-pane sliding glass doors in every room) in above-freezing temperatures, so there's no way to compare heating performance with you. I can say that the Pendleton does fine in my situation and my 70k BTU gas furnace stays cold for weeks at a time when I am using the stove and works reasonably hard when I am not. My only complaints with the stove are the touchy, non-repeatable draft control, and smoke and ash release when the door is open.

Eddy

 

[webbie]

I think the single wall portion of the top - even thought there is an air manifold below it, would transfer most of the heat from the portion behind it. Have you tried the thermometer there..and if so, what did it read?

 

[mickydean]

Welcome micky, I added some paragraph spacing to make more readable. Complete sentences are nice too .

How well seasoned was the wood burnt last year?

Regarding the stove, is it on an exterior chimney? Does it have a full liner and is there an block off plate installed below the damper? If not, that will improve it's output.

The wood I used last year was seasoned over a year. As far as the chimney goes, it is an exterior chimney. Not sure, but I believe there is no damper as on the old "heatorlator" fireboxes the dampers were part of the ceiling of the firebox- which was cut out to make room for the stove...thanks, Micky

 

[mickydean]

[quote author="Webmaster" date="1199749812"]Question - is the 400 degree temp you mention on the single wall portion of the stove top?

Do you have a tight sheet metal plate which seals off the fireplace - level with the lintel on a horizontal plane? Without this, a lot of heat will escape up the chimney.



There is insulation which seals the gap between the top of the stove and the top fireplace opening- and covered with a cast iron plate. There is less than a quarter inch gap on the sides which is uninsulated. Micky

 

[mickydean]

[quote author="EddyKilowatt" date="1199754741"]Webmaster --
Do you have any way to measure flue temperature at the stove outlet? That would be a good clue to how hot your fire really is. I use a Tel-Tru probe-and-dial type thermometer at the flue collar, and generally see 700-800F during a hot burn (the kind that will get the stove over 600F if it lasts for an hour).



I have no way to measure temperature at the flue collar.

 

[webbie]

Read this and the linked block off plate article:
https://www.hearth.com/econtent/index.php/wiki/Why_damper_seal_is_needed/

 

[mickydean]

Webmaster: thanks for the link to the damper seal. The "professionals" that installed my insert indeed left that one component out of the install. I need to give them a call. Thanks, Micky

 

[EddyKilowatt]

I think the single wall portion of the top - even thought there is an air manifold below it, would transfer most of the heat from the portion behind it. Have you tried the thermometer there..and if so, what did it read?

Just to follow up on this, I did an A-B-A comparison last night between the Condar surface temp thermometer on the front face of the stove, and the same thermometer moved to the top of the stove just in front of the air shroud (about 4" back from the front efge of the top plate). I was about 45 minutes into a "medium rate" burn of mixed pine and eucalyptus, with flue temperatures at the flue collar hovering within 25 degrees either side of 600F for that period. Under these conditions the Condar indicated 475F on the front face and 525F on the top. Again, based on three years' operation of this stove I would put these operating conditions into the "medium output" range... the stove can happily make less (although secondary becomes a little more iffy), or a fair amount more... but I have never seen a surface temp over 650 and would regard anything over 700 as a real eye-opener.

I also took another close look at the firebox, air channels, and warm air shrouding, and must still insist in a friendly way that there is no place on this stove where there is only a single layer of metal between the fire and the room. The top air channel gets direct flame impingement on its inner wall, and obviously runs the hottest, but it does have a steady flow of combustion air through it... and between the double wall and the airflow, this seems to keep exterior surface temperatures on the low side by woodstove standards. I kind of consider this a feature at least from a safety standpoint, although it does mean that convection plays a bigger role than radiation in this stove's operation... probably a by-product of it's dual-use design as both an insert and a freestander.

Micky, sounds like lack of a block-off plate will be a big part of your problems... I look forward to hearing how your stove performs once things are better sealed up. FWIW I will put in my usual plug for the usefulness of a flue-temperature thermometer in operating your stove; mine is the single most useful indicator I've got (and being a gadget nut I've got several) for how the fire is doing. Your insert complicates things a bit, but these

Tel-Tru Dial Thermometer (no connection, just a satisfied customer)

industrial dial thermometers are available stock with 12" and 18" stems, and I expect one could work out a way to get the stem end into the flue while the dial is mounted on the front plate.

regards,
Eddy

 

[mickydean]

thanks Eddy for the info on the flue temperature thermometer. I have a call out to the original installers about the flue block-off plate, see if they get back to me.

For anyone out there: with the directions to the block-off plate, there is no mention as to the weight or gauge of the sheet metal- what would be appropriate? Thanks, Micky