Looking for the Best Coal Stoker for My Applicatiton.

Hi Folks, Looks like an awesome forum you have here.
I'm looking for a stoker boiler to heat my home and domestic hot water. I live in Central Pa and have a 2400sq ft living area and a 2400sq ft basement. Currently I have an Oil fired hotwater baseboad heater I have not used for the past two years and rely solely on a Harman stoker stove in the family room upstairs to heat my home. Needless to say, some days it gets pretty cold in the house and there is no heat in the basement. My wife does not want the coal dust upstairs anymore, so this leads me to where I am today. I've been looking at sytems from Harmon, AHS and Axeman-Anderson. Things that are important to me are:
1) Broad heat range output - I'd like to heat my domestic hot water as long as possible in the fall and spring.
2) Ease of use
3) 2 - 3 day burn time - so I can go away for the weekend and still retun to a warm home.
4) Power vent would be nice so I wouldn't need to build a Chimmney
5) Low maintainence
6) Last forever.... at least 40 plus years
7) Costs less than $7000 for total installation.
Thanks in advance for any input.

Hello MXer, welcome to the forum.

You are looking for pretty much the perfect setup. I don't blame you.

I think the AHS or Axe-Anderson are going to allow you to burn earlier and later into the season, maybe even all year if you use enough domestic hot water to make it worthwhile.

The limitations I see are the desire to have 2-3 day untended use. This will be limiting during cold weather. The size of the coal hopper and maybe more importantly the ash pan may limit you to 24-36 hours between filling and emptying. What I do is geve access to the house to a friend and show them how to fill the hopper and empty the ash pan.

I would recommend building a chimney, a power vent is just another maintenance item to deal with. A masonry clay lined chimney will last as long as the house and boiler. If you build the chimney inside the house walls it will draft well into the summer, providing it is tall enough and unobstructed by trees or other buildings.

I would add EFM boilers to your list, they are very high quality, and built like a tank. Properly installed I believe they are close to the effeciency of the AHS and AxeAnderson. For a bit less money.

Hope this helps

Greg L

Thanks for the quick response Greg. The Ash pan size does seem to be the concern for 2 - 3 days unattended burn. I noticed you didn't comment on the Harman Stoker Boiler - I can trade my current Harman in on the Harman Boiler, but I won't let that effect my decision if the other boilers are better. I have not spoken with anyone about the EMF, I'll have to make that call. As far as Chimney's - What if I went with a Stainless insulated Chimney on the outside of the house? I had a mason tell me he thought they were better than masonary Chimney's.
Thanks again for all you help.
Steve

The problem with any metal chimney and coal is that coal and coal fly ash are acidic and will eventually cause corrosion problems with any metal. Less with stainless steel, but it too will eventually have problems

A clay lined masonry chimney will last just about forever.

I don't know the financials of your trade in for a Harman Boiler. I think there are several Harman boiler owners on the forum, hopefully one of them will offer their opinion. From what I know, the Harman is a good unit, but not as effecient or sophisticated as the AHS or AxeAnderson.

Greg L

I'm on my fourth season with my AHS boiler and can comment with confidence on your list of objectives. First it's a good list and has all of the items I would put on my list. My AHS installation is still a work in progress. I'll be installing a indoor-outdoor temperature aquatstat for matching the BTU output to the weather demand. The optional ash temperature probe would allow year round operation at a reasonable summer coal burn rate. This probe measures ash temperature and turns on the combustion blower to assure the fire does not go out. The unattended burn time is dependent on the size of the coal hopper and the ash pit volume. A custom coal hopper could be made as large as needed, only limited by space needed and by a practical method to fill it with coal. The boiler could be installed on a concrete base to increase the volume of ash storage. Enough capacity for 2-3 days of coal and ash capacity at rated BTU output would require larger than standard sizes.

While a power vent is not available from AHS, there are owners that have replaced the fixed speed combustion blower with a variable speed motor drive. This permits direct venting. The blower motor is always operating at a very low speed. Installation without a barometric damper and a tightly sealed exhaust duct system could make it reasonably safe if there would be a power outage. Annual maintenance on my AHS is less trouble than on my oil burner boiler. The AHS boiler will likely have longer life than the similar A-A boiler because it uses a ceramic heat shield where the combustion gases turn in the boiler tubes. The A-A boiler uses a steel plate. $7K would cover equipment costs especially if you are not building a chimney.

I'd recommend an indirect fire hot water tank for domestic hot water. It will have less standby loss in summer than keeping the boiler water hot all the time.

If a worst case power fail design on a power vent is important to you, I would suggest a much smaller second combustion blower to exhaust the idle operation flue gases. This smaller motor would be practical operate from a UPS. You would be on your own to engineer this solution.

as far as chimneys go, build a block and clay lined 8/8 chimney, cheap as hell and for coal, about the best you can get.

Thanks everyone - Maybe the mason I spoke with was thinking more along the lines of wood fired boilers instead of coal and the acid the smoke contains.
Hopefully someone here can chime in about the Harman boiler before I make my decision.

Hello Mxer

You may want to view the thread, Keystoker or Harman which I started a month or so ago. I researched all the available choices, and finally made my decision for the Harman.

I picked up the boiler this last weekend so I have no experience with it burning, but I can tell you that I am very impressed with the quality of construction. The boiler is 1/4" steel plate contstruction. Most of the welds appear to be machine made, and fit and finish of the unit in general seems top notch. I do have experience with the Harman stoker which is the same as the Magnum and is very well built. Holding a fire for 3 or 4 days with 250# hopper shouldn't be too tough unless the weather is very cold.

In your first post you stated that you wanted to keep your budget within $7000 including installation. You could certainly do this with the Harman or a Keystoker, not sure thats doable with an AHS, Axeman, or EFM boiler.

Lastly, on chimneys, I know most people would reccomend a masonary chimney, but I would also consider one of the better insulated metal chimney systems. Interior masonary chimneys are fine, but exterior ones tend to run cold. Cold chimneys do not draft well,and coal boilers, especially the newer ones do not have high flue temps, especially when they are coasting in warmer weather. The Harman boiler installation I visited had an exterior block chimney and the owner had to use a draft inducer to help it along.

I would look at chimneys with a higher grade nonmagnetic inner liner which are more resistant to corrosion.

Good Luck with your decision.

Hello MXer you can not go wrong with a E.F.M. they been around for over 75 years they make them very easy to matained and service and there made in PA so if you would ever need parts you would not ever have to worry about getting them also there are over 100 dealers in pa go to there site and see if there are any near you and give them a call for a price http://www.efmheating.com I know around where I live there are units in service for 60+ years almost all of my family members ether have or had one of them at some point. and almost all of my neabors have one as far as the ashes goes all you need is a few 1 or 2 bushell tubs both the round and square galvanized will fit the round 1 bushell tub will hold around 2 days of ashes the 2 bushell square tub will hold 4 days of ashes and for your coal bin you can build one next to the unit and feed right out of the bin or if you do not have the room you can use a 55 gal. drum that will hold enuff coal for 4 to 5 days it depends on how your feed is set up on the unit so if I where you I would check them out I hope this helps and good luck on finding one that works for you and if you go and pick up a papershop magazine you will find some used and rebuild ones for a good price in there as well http://papershop.com/ well take care and good luck

Highlander wrote:Hello Mxer

You may want to view the thread, Keystoker or Harman which I started a month or so ago. I researched all the available choices, and finally made my decision for the Harman.

I picked up the boiler this last weekend so I have no experience with it burning, but I can tell you that I am very impressed with the quality of construction. The boiler is 1/4" steel plate contstruction. Most of the welds appear to be machine made, and fit and finish of the unit in general seems top notch. I do have experience with the Harman stoker which is the same as the Magnum and is very well built. Holding a fire for 3 or 4 days with 250# hopper shouldn't be too tough unless the weather is very cold.

In your first post you stated that you wanted to keep your budget within $7000 including installation. You could certainly do this with the Harman or a Keystoker, not sure thats doable with an AHS, Axeman, or EFM boiler.

Lastly, on chimneys, I know most people would reccomend a masonary chimney, but I would also consider one of the better insulated metal chimney systems. Interior masonary chimneys are fine, but exterior ones tend to run cold. Cold chimneys do not draft well,and coal boilers, especially the newer ones do not have high flue temps, especially when they are coasting in warmer weather. The Harman boiler installation I visited had an exterior block chimney and the owner had to use a draft inducer to help it along.

I would look at chimneys with a higher grade nonmagnetic inner liner which are more resistant to corrosion.

Good Luck with your decision.

To add to highlanders reply ; should you decide on metal chimney , highlander mentioned going with the better grade stainless for coal. He is correct. The better grade stainless is "316" grade. You wouldn't want the "304" grade stainless for coal.

yup and if you get it the 316ti is the best, however I would still reccomend strongly against stainless if you can do masonry.

It's looking like the Harman Stoker boiler for me. I have a great dealer nearby who is willing to trade my Harman Magnum in making the total cost with trade - $3,699. It appears to be a very well built unit and for the additional costs, I can't see getting the AHS, A-A or EMF. I was leaning towards the AHS, but it wold have cost me another $2500 (Maybe not that much as I could have sold the Magnum Stoker privately). On the Harmon, the 250lb hopper has a stated 3 - 5 day unattended burn time. (unless burning hard) output of 5,000 to 95,000 BTUH, which is good for the low burn season and can burn as little as 1 lb per hour and stay lit as I understand. I want to offer a sincere "Thank You" for everyone helping me work through this decision.
As for Chimney - I still need to do some homework, but I am leaning towards the 316 SS Chimney due to it being located outside the house and I believe it will give me a better draft over a clay lined masonary Chimney. I'll post back to let everyone know how it goes.
Thanks Again
Steve

I spoke to AHS yesterday. They have an "April Special" going until next week for $4500.

I like the clean design and construction of Harman products.

Charlie Z wrote:I spoke to AHS yesterday. They have an "April Special" going until next week for $4500.

I like the clean design and construction of Harman products.

Unfortunatly the clean design doesn't equate to efficiency. At the special price, the AHS is a much better deal and 40,000 more BTUs (and probably burning about the same amount of coal). Selling your present stove privately and going with the AHS makes more sense to me.

I would go with a masonry chimney, there is nothing better.

Just spoke with Jeff at AHS and he confirmed the $4500 is good till Monday - Plus he is considering a trade for my Harmon!!! That would be sooo...weet! I am stoked..