Vermont Castings Merrimack

Still enjoying this insert. Test is snow forcast for tonight and tomorrow, something unusual for NW Oregon in November. Or December for that matter. Takes some practice loading fuel into double doors, so I usually just use the right one unless the log is really long. Put a 22" in yesterday and discovered it is a good idea to use a glove. Lots of hot parts. Still get smoked glass after a day of burning, even with the air flow wide open. But the newspaper/ash works fine. My roller bearing nut on the door latch worked its way off - if it was a reverse thread it wouldn't do that. So just used an allen wrench and the doors fit snug.

I had my Merrimack installed late October. I have been using for about 3 weeks and I have the following observations

1) Looks great...best window view for the size.
2) takes about 30-45 minutes to heat up enought to start the fan
3) heats my 1600sq ft drafty old (1945) house to a comfortable 72 degrees in about 2 hours
4) fan is a bit noisy on the high setting
5) I uusually start my burn about 630pm and the fire will burn for 5 hours on about 5-6 reasonable size pieces of wood.

So far I am very happy with my purchase. I looked for several years to try and find a great looking insert and I think the Merrimack is the best I have seen. The only comparison for looks/functionality/heating/viewing area has been the Jotul's..

Guy

Hi Guy,

Scott here. We got a Merrimack early this month. Agree with your observations. Are you having smoke glass issues? Also, I've had the "Pawl Assy Roller" on the door handle fall off. Tried tightening with a hex wrench, but it works its way off every two days or so. Seems like the threads on it should be reversed so it would always tighten itself.

Question for Guy and Elevator Man (and any other new Merrimack owners):

Now that we have experience firing our Merrimacks, I'm trying to figure out just how much wood to load into the firebox. On page 12, under Fig.12, the manual says "... be sure to fill the firebox as completely as possible by loading the wood pieces alternately on the left and right..." This is done over an ember bed of 2"-3". Also it says to keep the wood behind the Andiron. In my case all my fires are behind the primary air hole. Are you putting wood all the way to the front, up to the Andiron? I'm wondering if my smoked glass is because I'm not putting enough wood in? On the other hand I don't want to over fire the insert and cause it to "glow". That would not be cool; no pun intended.

Scott
Somewhere west of Banks, Oregon

Scott,
I have not had an issue with the handle yet. I usually only fill the stove at the start with 4 pieces of 16"x4"X4" (medium sized) and just keep adding a piece as needed when the pieces burn down. You definately want the bed of embers. I keep the wood behind the guard rails but do load up to the rails, and yes the window clouding I believe is due to not burning hot...i usually burn hot for the first hour and then turn down to keep the fire smoldering...if you want to see a clear fire you have to keep the flames hot and so you have to give it oxygen (handle to the left)....

Guy

Any issues relating to a hazing on the glass (or any other issues to be aware of)? Before I buy a Merrimack I want to be sure of any problems, especially since it is a new model. I would assume that the glass might get a haze from the type of wood burnt or a low burn temperature, but I want to be sure it is not a design issue as most other high efficiency stoves claim that most glass discoloration is burnt off...

Also, does the cast iron shelf on the Merrimack and the cast iron surround get hot or just warm?

Thanks for all responses. This is a great forum and I appreciate all the fantastic people providing information to a newbie!!

I was the one whining about the smoke on the glass. Well, I read the manual... I was under firing the insert. The last three days I've put a pretty good load of Douglas-fir in the beast, all the way up to the grate. I must admit it is a bit disconcerting when the flames lick the glass. And when the temperature is at its peak, the gasses off-burn above the fuel and we find ourselves mesmerized by the site. In the morning, when the fire is 99% out, there is a bit of smoke on the bottom half of the glass. But it wipes off with a damp rag or paper towel. So the design works.

The top does get hot enough to burn skin. It actually is removeable, so it is heated indirectly. If you're thinking about boiling tea water on top, well, good luck. (I personally think a pot on top would distract from the design.) The doors do get hot, so I use leather gloves to load new fuel. (burned my finger the second day; Darwin experiment)

Take a look at the manual online and see the diagrams of the parts. Probably 80% of the insert will be behind the face plate. I was surprised that the back part didn't look like cast iron - it is some sort of steel surround, designed to take heat away from internal cast iron and blow it out the top/front. The diagram sort of shows that. Compared to my old wood stove in 1981, which had four parts, I guess effeciency is due to technology.

Scott
somewhere west of Banks, Oregon

I also have a Vermont Casting's Merrimack installed in my home in Southern Maryland right on the Potomac River. The house is a poorly insulated 2000sqft single floor cottage style home with a living room that is about 26'x14' with about 16' of windows lining the wall facing the water. The Merrimack is on the opposite wall. Needless to say, those windows create a very chilly family room, but the Merrimack definitely solves that problem. I have found it adequate to provide about a 30-40 degree temperature differential between outside and inside at a reasonable burn rate (say fan at 40%, mature fire, damper in lowest airflow position). By temperature differential I mean that if it is 30 degrees f outside then I can keep it about 70 degrees f inside.

I do experience mildy smoking of the glass, but only when it is being under-fired. If you keep it roaring and hot the glass is very clear.

The most significant issue I have is the noise generated by the blower. I actually think I may have a defective blower because it is so loud. I will contact Vermont Castings to verify... anyone if there is anyone out there who is a sound / audiophile and can take decibel measurements I would appreciate comparing notes.

For the measuring setup, the fire is roaring, the fan is on and I varied the speed by percentage (left colum), the right colum is the decibel A weighted measurement at a distance of 15" from the the front of the Merrimack. The measurements were taken using a RadioShack sound level meter that I trust and routinely use to calibrate home theater surround sound systems.

Here are my rough sound measurements:
Fan Speed - Sound level
10% - <50dB-A
20% - 52 dB-A
30% - 54 dB-A
40% - 55 dB-A
45% - 57 dB-A
50% - 59 dB-A
55% - 60 dB-A
60% - 62 dB-A
70% - 64 dB-A
80% - 65 dB-A
90% - 67 dB-A
100% - 69 dB-A

For a reference on sound equivalents in decibels, see this wikipedia article:

http://en.wikipedia.org/wiki/Sound_pressure#Sound_pressure_level

The bottom line is that anything over 55dB-A in your living room is going to be VERY annoying. 69dB-A is equivalent to listening to a loud electric mixer in your living room all day long... not pleasant! This is why I think mine must have an issue, I couldn't imagine this design would get past the testing stage.

I will provide an update when I hear from Vermont Castings. I suppose it will also be a test of their customer support!

If you are interested, I posted a Youtube video of mine with the fan running at full speed, I am sure you will agree it is a bit ridiculous!

http://www.youtube.com/watch?v=Ibmz8PqcjBE

I must admit that I love the looks of this thing though. If the blower doesn't have an issue and this is just how loud it is, I will probably design and fabricate a replacement for it myself.

Merrimack Fan Sound... yes, ours is loud at full blast. So I am interested in what VC says about their fan. It would seem like they could spend an extra fifty bucks on a silent (aka, German made?) fan. In our case when we fire our insert in the mornng, the damper is wide open and the fuel stack roars. I set the fan on high and when it turns on when the temperature is reached, we just ignore it until the room temp comes up and the fuel bed is ready to reload. As posted in an early post, I read the manual on how to fire and such, so now we have a minor glass smoke issue.

Once we are at room temperature, we find we only add two our three sticks of splits to the fuel bed every three or four hours, keeping the fan on low and the damper at about 95% closed. Keeps the temp in the house constant.

Our house is a 1999 with good insulation, and tight. So we can get a 40 degree temp rise, which like today it is 40 out, I must be careful to not over load fuel or we will be in shorts and T-shirts inside!

I would agree with your fan noise level measurements. The high is like a cheap bathroom exhaust fan noise. Annoying...

Scott
somewhere west of Banks, Oregon

Merrimack Fan Sound... yes, ours is loud at full blast. So I am interested in what VC says about their fan. It would seem like they could spend an extra fifty bucks on a silent (aka, German made?) fan. In our case when we fire our insert in the morning, the damper is wide open and the fuel stack roars. I set the fan on high and when it turns on when the temperature is reached, we just ignore it until the room temp comes up and the fuel bed is ready to reload. As posted in an early post, I read the manual on how to fire and such, so now we have a minor glass smoke issue.

Once we are at room temperature, we find we only add two our three sticks of splits to the fuel bed every three or four hours, keeping the fan on low and the damper at about 95% closed. Keeps the temp in the house constant.

Our house is a 1999 with good insulation, and tight. So we can get a 40 degree temp rise, which like today it is 40 out, I must be careful to not over load fuel or we will be in shorts and T-shirts inside!

I would agree with your fan noise level measurements. The high is like a cheap bathroom exhaust fan noise. Annoying...

Scott
somewhere west of Banks, Oregon

Our Vermont Castings Merrimack was installed 8 days ago. We did the 3 small burns to break it in, have had 3 large burns since then. It worked nicely until THE FAN WENT OUT TODAY. So we are now slowing down the burn by shutting the draft as much as possible, will allow it to go out, and call the installers on Monday. Just what I feared! Seems they haven't solved the problems yet.

P.S. It's now the next morning. The Merrimack is cold, and now the fan is running. Clearly, the thermostat has gone kabluey. In fact, I am pretty sure that the thermostat circuit board has a cracked line on it. As the circuit board heats up, the crack opens, the thermostat no longer works. We just proved that by starting a new fire. As we opened the doors, letting in cool air from the room, the fan stopped. We started a fire, the fan came on at an appropriate time, and ran until the unit got to 400 degrees, then the blower cut out again.

Here is my assessment of the Merrimack. I believe our old fireplace was pretty efficient. It was built with heatilator and fans - in my avatar you can see an air intake opening to the left of the Merrimack. (The grill has been removed for repainting.) A second opening lies behind the fireplace tools. We had fans in each of these intakes, circulating air behind the firebox, with exits built into the granite block face about midway to the ceiling. We also had iron doors we could close to keep the fire burning all night. We were able to load up the old fireplace, shut the doors, set the firebox air flow using a custom-built variable-opening air intake system at the bottom of the doors, partially close the chimney damper, turn on the fans, and keep our house toasty through winter nights. The Merrimack puts out as much heat as the old fireplace, but with fewer logs (i.e. a more efficient burn), but the total burn time is not as long - due to a smaller firebox combined with the limited range of the Merrimack air control lever. We like being able to see the fire through the glass doors, but miss the immense hot fires we could stoke up in our fireplace when we used it with the doors open. Tradeoffs. We will need less wood this season, but we will miss the occasional hot, open fires with dog and cat sitting on the hearth, fur steaming.

And why did we replace that fabulous old fireplace with this insert? Cost. The old firebox needed to be replaced, which meant taking down the granite block wall once again, rebuilding a lot of stuff inside, and rebuilding the facing. Total cost would have been at least twice what we spent for the Merrimack, plus weeks of granite and cement dust everywhere in the house. We have been through that before. Here's hoping I don't regret my choice before spring.

And regarding questions about haze on the glass doors: folks, these glass doors are going to be a snap compared to the old iron doors we had on the fireplace. The circulation system inside the Merrimack sends hot air to the doors, keeping them pretty clean. The deposits on the inside of our old iron doors got really thick, and cleaning was a half-hour of dirty, dirty scraping work.

If I could order the Merrimack with changes, they would be these. 1. An option for quieter fans. I would pay quite a bit more for better fans. 2. Option for a larger range on the air intake lever. Ought to be able to shut it down farther.

I'm going to add a coda here on fan noise. We have been running our Merrimack fans at about 30%. Noise is substantial but not overpowering. This meshes with the great noise level measurements done by WhitePointBeach. At 30%, the fan noise is less than the noise we had from our heatilator system. The variable control on the fans is wonderful. We all need to remember that a lot of the fan noise is due to the path the air takes through the heatilator, not the fans themselves. In our old fireplace heatilator, we had installed "whisper-quiet" fans, but 4 fans plus a contorted path for the air meant lots of noise. Lets thank VC for the ability to control the noise through the variable speed regulator.

Can you ask the dealer if VC is going to work on the fan noise issue? This might be a deal breaker for future buyers who check this website before making a purchase. We still like the look of the unit...

Have had the Merrimack installed and burning for about a month...a couple observations...

1) Great heat output...burns us out of the room if we let it
2) Short burn times...if i pack the firebox with wood i get only about 6-7 hours...wake up in the morning to only a few embers
3) When i open doors to load i get alot (i mean A LOT) of smoke back into the room, although this may be a factor of chimney...working with installer to figure out...
4) Fan is LOUD at full speed...replaced a 1979 Tremont with this unit and i think the fan on the ancient beast was as loud or quieter...
5) Great looking and the glass has never gotten dirty...had a friend today who knows woodstoves comment on how clean the glass stays
6) Going through a tremendous amount of wood...guess it goes back to point #2...thought I would burn less than the old unit but this is not the case...

If anyone has any recommendations to solve any of my problems i'd appreciate some feedback. Hope my brief synopsis of what i'm seeing in the unit helps folks decide what they want to purchase.

...one more observation...when i back the stove down on air it still burns to a degree that consumes alot of wood...not much a difference between wide-open and fully scaled back...don't know if this is a factor of EPA requirements or not...probably a reason why it burns so much wood (OAK)

We have also had our Merrimack about a month.
1. Like the look.
2. Efficiency somewhere between 60-70%, as stated on a card with the insert. A person posted whether the Merrimack qualified for the $1500 federal tax credit; the dealer says it does, but the poster said the law had a 75% minimum efficiency rating. Hum.
3. Either way, it beats feeding wood into an open fireplace, something we did for 11 years. We use about 1/5 the amount of wood (Douglas-fir) and heat our entire upstairs (the room is 48' x 75' x ~16' at the ceiling peak).
4. The fan is too loud on high. Which presents a problem, to keep the glass clean you must fire at a high temperature... which requires a high fan setting to avoid overheating the unit. A smaller fire, using a few splits of wood, burns slowly, but does smoke up the glass.
5. We don't load up the unit at bedtime to try to keep it going all night. (Something about a fire going upstairs when I'm asleep. Just call me paranoid.)
6. If you open the right door quickly, especially if the fuel is still flaming, smoke is easily drawn into the room. I wait until there is a bed of glowing coals, then load up the firebox. The manual says to cross-stack your fuel, and when you do it that way, the hot fire keeps the glass clean. But then you're back to keeping the fan on high if the box temps get too high.
7. I use a pair of welder's gloves to load fuel into a hot stove. Rather burn leather than my index finger (again).

Tomorrow I'm going to call the dealer and complain about the fan noise. Maybe dealers can pressure Vermont Castings to address this one, and in my opinion only, quality control issue. In hindsight, would I still buy this insert? Yes.

Hi everyone, new to the forums.

i moved into a house that is about 2500 SQ feet, 3800 SQ FT including the unfinished basement (Colonial Style in PA).

There is a family room with a fireplace that is completely inefficient. I am looking for a wood insert and I was suggested by the local fireplace dealer that a merrimack would do wonders. I am looking to heat the house and not just the family room. My house does not have an open floorplan, just hallways connected. The dealer said since i have a house fan with return vents the heat should be taken to the rest of the house. I do not need the basement heater as its unfinished more concerned about the living room, dining and bedrooms. I have never owned a fireplace before so is what the dealer telling me true?

I also see that their are several issues everyone has posted.

Fan issue- did anyone get this resolved?
glass issue - i could live with it
lastly the most important to me is the tax credit - is the merrimack not covered? I was qouted with install 5,100. The dealer said it was covered, anyone have an answer?

Any help would be appreciated as im running out of time in 2010 to take advantage of tax credit.

Be careful of that dealer...The best price on the stove I found was in Connecticut for about $2200 plus 550 install www.cafd.com. Hell, the stove has a list price of 2495 I believe (without surround). The install runs between 500-600, the liner about the same. You should not pay more than 4300 for the whole thing, stove, liner and install. Insulated liner add 350 (Look at the beginning of this thread).

Appropriate airflow is needed to heat a whole house...especially one your size. I think that dealer is trying to take you for about 800 more than he should and promising you too much.

After careful consideration we went with the Jotul 550 as it seems to have higher quality construction (in my opinion) and is proven. The Merrimack is a new model this year. Both the Merrimack and the 550 are eligible for the tax credit.

thanks for the quick reply, i am also going to look at the jotul. Does the jotul heat your home pretty well? i assume the jotul doesnt have the fan or glass problems people with the merrimack are seeing?

also thanks for the advice on the merrimack if i decide to go with it i am definitely going to shop around.

no prob....I lurk to learn as our Jotul is on order and will be installed next Tuesday (can't wait). For us and our evaluation criteria, the Jotul won out but the Merrimack looks like a great stove and I am sure it will serve owners very well. We have a fairly open floor plan and I assume the stove will heat the 1st floor when we use it, but I would not expect much heat to get upstairs and heat the bedrooms terribly much. I view the estimates that the brochures say (max sq ft it heats and btu's) like car EPA estimates...just a guideline and under perfect conditions (not likely). Air movement is key in either case and the more rooms that are closed off by the design of the house, especially upstairs, could be tough to heat.... can't expect heat travel everywhere throughout the house, but your house fan will help.

Good call on the shopping around, can't hurt. Just do your research and feel comfortable with your purchase. For the tax credit it must be purchased and installed before Dec 31....I would defiantly purchase it before Dec 31...what date the installer puts down on your bill could be "negotiable"..lol Keep in mind your insurance company and/or your town might require a permit/inspection also.

This is my follow up on fan noise and contacting Vermont Castings directly about it. I thought I might be able to open a line of communication directly between myself and VC but I have not been able to. Per their website they request all communication about their products take place between the end user and the dealer. I find this mildly problematic because while I consider the fan noise to be excessive, I think the members of this board all share the same issue so it is most likely not a "defect" per se but the actual function of the unit as designed. So I doubt the dealer can offer anything other than a "sorry about the noise". It would be Vermont Castings and their engineers who could not only potentially offer a solution, but take the feedback and integrate it into later revisions or updates of the Merrimack design. VC... if you are listening... demonstrate your best in class engineering and interest in the customer's well being by engineering a less noisey product. A lot of us consumers are putting these things in our living rooms, right next to our HDTVs and surround sound systems. It is not acceptable for a newly designed insert to sound like a 20 year old dishwasher. At full speed I request a maximum sound level of 50dBA at 15" from the front of the Merrimack at maximum fan speed... VC engineers, make note and add it to the requirements list. If you achieve it and advertise that feature buyers will notice. I expect more from an American engineered and fabricated product... please live up to my expectations... I will pay more for better!

In my opinion the design of the blower system is very weak. The sheet metal the blower is mounted on is barely adequate and vibrates with the motor and fan. The motor and fan are not well balanced and thus generate the vibration and associated noise. I understand that 130 cubic feet per minute (CFM) of air blowing through an iron to air heat exchanger will make some "wind" noise... but that is not my problem, my problem is the mechanical noise and vibration. I may try adding some reinforcements to the sheet metal to reduce the vibration. Then I may add some sound deadening material such as Dynil to see if I can soak up some of the noise. I will keep you all posted regarding my experiments.

Can anyone tell I am an engineer?

In all honesty this situation has me very interested in these blower designs. They seem to be plain silly and an afterthought. The other build quality of the refractory brick and interior of the Merrimack is impressive. I think the glass wash system works reasonably well. I find that if I only open the right door slowly and let the draft build up for 10-30 seconds before opening it fully I have no problem with smoke entering the room.


Back to the blowers... I have also been thinking about an "optimal" design. In my mind it seems like it should be quiet and should probably have the airflow in the opposite direction (air coming out of the bottom). I think it would be fabulous if the blower could generate a laminar flow of warm air that just rolled out across my floor for 6'-8' or so and then gently rose up into the room. It could even keep the floor nice and warm. It also seems like the fan should be remote controllable via a handheld remote (simple on / off and manual speed control). I am sure there are many reasons that the air flows the other way, but I am curious. I think one of the more difficult problems would be that the fans would need to still be at the bottom and therefore would be sucking VERY hot air through themselves and thus generating a lot of internal heat. I am not sure how well electric motors and electronics do at 150-250 degrees for 6 months of the year on 24/7. Reliability is important. I may investigate retrofitting in a remote control system. My company routinely designs and installs very high end home automation systems and controlling a fan motor should be pretty straight forward compared to automating a whole house.

Anyway, if anyone has a contact actually at Vermont Castings in the engineering department or perhaps at the parent company, I would be interested in their contact info.

If I had to buy it again, I think I would because of the styling, window size, and thermal mass of cast iron... but the noise issue is a bummer. Fix the noise and I think it is an A+ product. Maybe it is like a new car... wait until the 2nd model year? Hopefully VC will be proud of their new remote control whisper quiet fan system (courtesy of the Hearth.com market research and engineering group)!

Great post W P B! I've been thinking for a while that wood stoves are lagging fart behind on technology. I get they are a thing that was used more frequently in the past. But that doesn't mean that they should be built like a thing of the past. Especially, since they're accompanied with a futuristic price tag.

thanks for the info, what im hearing here is that stay away from the merrimack as i know my wife would be annoyed with a loud fan.

i called a dealer today and they mentioned regency's are good, any thoughts on them. i tried searching the forums

Bought mine on Saturday, then found this site. Almost returned it on Sunday but decided to go with it.

The salesman told me it was a catalytic. Is this true? Does it have everburn?

Nope, not catalytic. Less maintenance, they say. We hope VC will deal with the fan issue.

How does it achieve the secondary burn?