Mt Vernon AE Insert heat output

[cavermedic]

Hi - our Mt Vernon AE insert seems to be really wimpy. We keep the heat output at 5 and the flame height at +5, and it still won't heat about 1600 of space. Below about 20 degrees outside, the temp gradually drops until the oil kicks in. The thermo (10 feet from stove, off to side) is set for 64, and the temp is usually around 59-61 (oil is set for 58). Right now, it's 8 outside and 61 on thermo. The far end of the Living Room, directly in line with the stove, is 59 right now (the dealership owner claims that our LR should be a sauna at the 5/5 settings). We've tried two different types of pellets (NEWP premium hardwood and ACP 80/20 premium) with no difference in performance. We are going through over 2 bags/day.

The dealer's service dude checked the stove out and said everything is working correctly. It seems to me like maybe the air output is really weak. The fan is blowing air - you feel it within a foot or two from the stove, but standing about 6 feet directly in front of the stove, you barely feel any air moving. I would think that on high speed you should feel a lot of air at that distance. Does this amount of air movement sound like what others with an AE insert feel on these settings? Any suggestions? Thanks.

 

[Gweeper64]

You are right; something does not sound right. I'm not having that experience at all.. We got our AE insert in mid/late January and we are burning the last bag of the first ton of pellets right now as I write this. I have a single level ranch with about 1500sq including a family room addition with a catherdral ceiling and skylights. My AE insert has been keeping the whole whose at about 68-72 most of the time. The oil furnace has barely run (except for the hot water) since we got the stove. In fact, I turn it on once or twice a day when it is extremely cold out just to keep the baseboard pipes from freezing.

I usually run on "automatic" setting. I set the thermostat temp at about 76. With a fan set up to move some air to the bedrooms and the ceiling fan on in the family room, the whole house stays at between 68 and 72. When it is real cold out (single digits), the stove runs on Medium to High a lot more. Otherwise, it runs on Low or Medium-Low (i.e. 1 or 2) most of the time. On average, we burn just under 2 bags per day. The few times I've put mine on High, it really cranked out the heat but it was also eating through fuel like crazy (a bag in 4 or 5 hours).

I also have been burning the NEWP premium. They seem ok, but I have no other experience to compare to yet. I have been cleaning the stove about twice a week, cleaning behind the baffle once a week.

Do you have the fan speed set on "Normal" or "Quiet" ? Mine is on "Normal" most of the time. Even on "Normal", I don't consider it too loud.

How well insulated is your house? If you've got a lot of drafts, it might have a hard time keeping it at temperature.

Have you compared the unit's thermostat temperature reading with another thermometer? Mine seemed like it was off by a couple of degrees initially. You can calibrate it in the User settings.

 

[kilbury]

Also check out to see if your elevation setting is set to. How is the exhaust vented?

 

[cavermedic]

Thanks for the feedback. The fan is on Normal, not quiet. I also already checked all the other settings like elevation. Our house was built in 1926 so it is not well insulated in the walls, but we have all new double-pane windows, extra insulation in the attic, and have weatherstipped/caulked all around. Our house is not drafty. We have been using 500-800 gallons of oil a winter, and that was keeping the house a little warmer than we have this winter.

There is plenty of flame (set on +5, reaching the top of the diamond), and the output is hot six inches in front of the stove. It just seems like the heat disappears once you get more than three feet away. Thank goodness for long undies and fleece!

 

[cavermedic]

Oh yeah - the vent is up the chimney, about 24 feet (typical 2-story colonial), 6" flex to the top. There is a large chimney cap on the chimney. I don't know how close to the cap the flex runs.

 

[stoveguy13]

do you have a 6" liner up the chimney? what pellet setting are you on?

 

[cavermedic]

Yes on the 6" liner all the way to the top. Hardwood for the pellet setting - thinking about playing with that, but haven't yet. It's not like the stove is "cranking" and then cooling down too often, so I don't think the longer time between clean-outs will be significant.

 

[stoveguy13]

why did they use a 6" liner and is there a top and bottom block off plate

 

[weatherguy]

I dont feel any air moving 6 feet from my stove wither, its hot if I put my hand a few inches in front. I had my stove shut down for a few days but fired it up last night since its cold again and it took til this morning to warm the house up again.

You sure you dont have 3" or 4" liner?

 

[cavermedic]

Whoops - I stand corrected. It's a 4" liner. I knew it was the bigger of two options, and remembered wrong. I'm not sure what Stoveguy13 meant by a block-off plate, but they did cap the top of the chimney flue with some sort of metal plate. They did not block the damper area with anything - darned near impossible to get to now with the stove was in the way.

I do have another service dude coming, hopefully Wednesday. He said that they have had one previous case of a convection fan not giving full output - I'm keeping my fingers crossed that he finds that to be our problem and doesn't just tell us to "suck it up".

 

[jtp10181]

I can't believe you an even run the thing at +5. Most stoves I have seen need to be set to - something so the flame is not huge and engulfing the entire firebox.

I would make sure the conv blower is engaged into the boot on the back. It is only held in with one pin so it can come out of its proper place if jarred. If the blower was not moving enough air or disengaged I would expect you to get Drop Tube TC errors and overheat errors.

I would clean up the baffle and exhaust pit in the back really well and see if that helps.

If none of that does any good I would suspect you are just expecting too much in an old house.

I was running a huge 5100i in an old house and the ceiling above it was 90F and the outside walls were still 70F or less (the same temp as when I got there).

 

[fluemasterjr]

I have installed alot of Mt.Vernon AE and have only seen a couple set to a flame hight above 0 and that was only due to a poor pellet. have you tried a different type of pellet?? are you burning in auto or manual mode?

 

[cavermedic]

We started out the winter at +1 (set by the installers). When we first started having problems with the lack of heat, the dealer recommended raising the flame height to +3. We did that for a while, with very little change. According to the dealer, the flame height setting affects the pellet feed rate, so to get the max heat possible I went up to the +5 setting. THe flame goes to the top of the diamond, sometmes slightly above and sometimes a little lower (we understand that the fluctuations are due to the pellet feed being uneven, which is supposedly normal). We are in manual mode, with a Normal fan speed and a High heat Output. Still very little additional heat output, though. We gave up on setback settings when the stove never hit even the setback temp. Unless it gets up to about 50 out (which it has twice so far this winter), the stove just sits there and burns lots of pellets.

We have only burned two types of pellets so far - NEWP and ACP. Both say "Premium Grade" on the bag (yeah, I know that this doesn't guarantee anything . . .). The NEWP is a good solid pellet (supposedly hardwood, although it doesn't say so on the bag) with very little fines and no dust. When we ran low on those, I couldn't get more locally and our supplier only had the Appling County pellets. The ACP is an 80/20 combo, shorter pellets, more dust and fines. We get a little more ash with the ACP, but don't see any difference in the flame or heat output. Luckily, our load doesn't stink like the ACP pellets are supposed to.

To answer jtp10181's earlier question - we have not had any error messages since the stove was installed.

Wednesday, a different service dude is coming. Suppsed to be between 5 and 20 outside, so he will get a good idea of how little heat it's putting out.

Thanks, all, for the input.
Steve

 

[Gweeper64]

Let us know how it works out. Being a Mt Vernon insert owner too, I'm curious what the problem is.

 

[Deed]

I have been and owner of a MT VERNON AE for the past two winters. I have a 1300 foot ranch. It has been quite cold here. I'm burn on average of one bag a day a bit more when it is below zero during the night and single digits or lower teens during the day. The house stays between 65 to 70 depending rather we are home or not. This stove could keep my house much warmer if desired. Not able to give you any suggestion about what the problem could be, just sounds as if there is a problem with the stove or you have little to no insulation in the walls or ceiling. Good luck finding the problem.

 

[fluemasterjr]

I don't have any experience with the acp pellets but from reading what others have said about them they are not the best quality. As far as the newp if you are burning them at the same setting as the acp pellets than they don't seam to be that good. I had a customer with 3 ton of newp first ton flame hight was +1 and the second ton at -5 if she turned it up to a -4 it was shutting down with max drop tube temp. that goes to show you how much pellets can vary from ton to ton. what is nice about the Mt.vernon ae the convection blower is a variable speed blower on this stove witch makes it very easy to tell if the pellets are a good quality. If you have a good quality pellet with the heat output on 5 and the flame hight at +5 the convection blower will sound like a freight train!! that is if it doesn't kick off with max drop tube temp. Rember anything over 8"steady flame is an over fire and WILL crack the baffle.

 

[cavermedic]

The good news - the service dude walked in the door, took one look at the flame height, made a face, scratched his head, and muttered "That ain't right!" The bad news - when he left two hours later, he was making a face, scratching his head, and muttering "That still ain't right!".

He totally agreed that on +5, we should have had a lot more flame than we did. He was also concerned about the variability in flame height - he felt it was more pronounced than it should have been. However, even after calling the factory, he couldn't come up with any way to change it (I think they suggested trying voodoo). He checked our pellets - they are the same as they use in their store, and they are high quality, so he doen't feel that they are the problem. He did change out the control board, but we didn't see any difference.

He did notice that the installers had not plugged the damper with any insulation. While it seems unlikely that this could be related to flame height, he is going to have someone come fix that. He is also going to look into whether a damper on the vent pipe might help. He felt that the auger was working properly, but he did time its rotation and is going to check that against a unit in their store to see if there is something up with the auger (we've never goten any error messages on this stove).

Things I will try in the meantime: I have a bag of softwood pellets that I swiped from a friend's stockpile that I'm gonna burn and see what happens with the flame height. And the next time I clean the stove, I'm gonna run the hopper out and look down it with a mirror to make sure that there's nothing partially blocking it. I'll update tihs when we (hopefully) know more.

Oh - and does anyone have a little stove-shaped doll I can use?

 

[stoveguy13]

what does the flame look like iot should be yellow hitting the center of the diamond try putting it on uttility zero flame height second tack out the baffle and give it a good cleaning and clean behind the ash pan.

 

[kilbury]

I have four units right now doing the same thing, just not enough flame height. I am trying to burn corn in these though. I can get a good flame height and good heat output with pellets but can barely get the flame out of the firepot with corn. All units are maxed out as far as flame height and heat output levels. As far as the damper goes, I have installed 2 of those on 2 serparat units and it has made very little difference. Let us know what he comes up with as I am pulling my hair out (or whats left of it) trying to get these things to put out any heat. It seems to me that all of mine are making way too much draft. I have also talked to the factory about this and we couldn't come up with a cure yet.

 

[fluemasterjr]

to the best of my knowledge quad does not allow use of a damper on there units.

 

[kilbury]

order them from them peldamp-3, more or less a choke type setup but is not able to completely able to block off the exhaust. Their instructions say for use on units with excess of 25' or excessive overdrafting.

 

[cavermedic]

what does the flame look like iot should be yellow hitting the center of the diamond try putting it on uttility zero flame height second tack out the baffle and give it a good cleaning and clean behind the ash pan.

The flame is yellow, not lazy at all, no excess sooting. On +5 it is hitting anywhere from the bottom to the top of the diamond. Weekly cleaning ritual includes cleaning behind the baffle, scraping off the fingers with a brush, vacuuming behind the ash pan, and running a 2 foot piece of garden hose attached to the shop vac down the two side pits. The shop owner joked that maybe I should let this stove get a little dirty once in a while so that it feels like a real stove.

 

[stoveguy13]

what fuel table are you running on?

 

[cavermedic]

Hardwood, although I just ran it on softwood for the last 24h to see if it made a difference (it didn't).

New SWAG from the service dude - when they pull the stove out next week to insulate the damper opening, they are going to check the tightness of the auger's set screw to see if maybe the auger is slipping on its shaft. If so, that could result in lower pellet volume, leading to lower flame height, etc. Worth a try, I guess. And Quadrafire dissed the damper idea.

Meanwhile, I'm still looking for a stove-shaped voodoo doll.

 

[fluemasterjr]

I have four units right now doing the same thing, just not enough flame height. I am trying to burn corn in these though. I can get a good flame height and good heat output with pellets but can barely get the flame out of the firepot with corn. All units are maxed out as far as flame height and heat output levels. As far as the damper goes, I have installed 2 of those on 2 serparat units and it has made very little difference. Let us know what he comes up with as I am pulling my hair out (or whats left of it) trying to get these things to put out any heat. It seems to me that all of mine are making way too much draft. I have also talked to the factory about this and we couldn't come up with a cure yet.

The MT.Vernon AE is only rated a 47,000 btus when burning corn. If the set screw was loose the auger would have slid down out of the motor assembly.