My keystoker KAA-4-1 boiler

leonz

I have fired up the stoker boiler tonight for the first time this season and I expect to have a much warmer house in a couple of hours. Judging by the lack of pinecones on the conifers around my place I think we will be having a milder but very wet winter, but time will tell.

When I wake up in the morning I know the house will be much warmer than the 56 degrees it was this morning 🙂.

I can keep the thermostat at 65 for at least 2 months and have a happy balance and a warm living room until I have to raise the high and low limit settings on my triple aquastat as I have it set for summer operating temperatures.

Steamhead

How about some pics?

Steamhead

Not sure why this double-posted- @HeatingHelp , please remove this.

leonz

https://forum.heatinghelp.com/discussion/comment/1906036#Comment_1906036

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The 30+ year old riello burner is gone and scrapped, I need a new oil tank and burner with a 2 pipe system if I am going to burn oil again. The oil tank is 32 years old and I would like to replace it with a highland petro hopper if I can no longer manage to burn coal anymore.

My keystoker KAA-4-1 has an Intermatic 30 minute timer that controls the amount of time the stoker runs to prevent an outfire where the fire dies completely and the ash pail is filled with unburned coal.

Leon

hot_rod

well it is certainly a clean machine!

A properly working BFD can spit from time to time, add the vent tube

Hate to see that Dwyer get hosed

leonz

Hello and good evening to you Bob,

The last image is almost 11 years old, I moved the Dwyer Mark II to the door a long time ago and it is safe.

I had the entire flue pipe replaced with new pipe 2 years ago and it makes cleaning the stove pipe easier as I have a Tee with a cap at the flue breech and a single sloped pipe to the chimney thimble which lets the fly ash fall back to the tee.

I remove the cap and pull the fly ash out with a gloved hand when I hear the CO alarm go off or I check the Tee every month whichever comes first. I have a new roll of high temperature tape to seal the cap off when I take it off the tee at the flue breech.

I just weighed the ash bucket and I apparently have generated only 6 pounds of ash since yesterday-YAY!!!

So far so good and we are heating up the house slowly.

Leon

PC7060

Nice setup Leon. Where are you located (state)?

Our Virginia low temps are 45-50F so we haven’t needed boiler so far this season.

leonz

Hello and good morning to you PC7060,

I am located near Ithaca, New York. I originally used a Switzer CWW100 hand fed wood and coal boiler. with an external domestic hot water coil and an AVCO LYCOMING oil fired boiler.

Knowing what I know now I would have done things differently.

I should have purchased the VanWert VA400 coal stoker boiler with the internal domestic coil and eliminated burning wood entirely. The VanWert coal stoker boilers and furnaces were underfed tuyere/burn pot stokers. What held me back from doing it was the installed price of $6,000.00 back in 1982. The installation cost of the CWW100 was $4000.00 at the time

When I wanted to purchase a pot stoker in 2014 the EFMDF520 was $10,000.00.

I have my stoker running on summer temperatures using 140 Degrees Fahrenheit low limit/160 Degrees Fahrenheit high limit using 190 degrees as the dump zone temperature. My 225 feet+- of 3/4" fin tube baseboard is used as the dump zone with one circulator. I normally turn the high and low limit temperatures up to 150 low/170 high or higher only when it becomes really cold later in the year.

I regret losing the Buderus boiler I had that was 33 years old as it never gave me a bit of trouble but saving it would have cost me $8,000.00 just for the installation cost plus the $6,600.00from another installer in 2014. The installation would have been better and I would not have had to deal with the clown car plumbers I dealt with that cost me $5000.00.

The plumbers I hired were the only ones that would install this coal stoker and there in begins the tale.

The use of the hydrolevel 3250 plus in the keystoker cost me a great deal of money as the digital controls failed on the first unit and the second unit as well. I replaced those units with a honeywell L8124L and a Bell & Gossett RB122-E direct immersion low water cut off. what really pissed me off was the keystoker people said that they could no longer obtain the honeywell mechanical triple aquastats which was a lie, I purchased two of them from supply house leaving one new one as a spare which I probably will never need anyway.

Keystoker had 64 of the hydrolevels returned as failed by the time I had the first one fail that let the boiler run away. The problem with them is that those things were only ment for cold start gas boilers not coal stokers.

It was convenient for hydrolevel to eliminate the verbiage on thier owners manual/installation manual stating that these units were only ment for cold start gas boilers. The EFM and Axeman Anderson stoker makers still have units that fail since they no longer supply their stokers with the honeywell mechanical triple aquastats.

I figure if the 4 inch guage's they supply do not have the name of the manufacturer on them or their address I do not want them on my boiler.

When they connected the domestic hot water coil to the plumbing they used the viega propess fittings and they blew apart and ran my well dry. I did not have a potable hot water expansion tank plumbed into the cold water side of the domestic coil of the coal stoker but I never had a problem with the external domestic coil in the CWW100 in the 33 years I had the hand fed wood and coal boiler; maybe that was on me, I am not sure but I would like to have it hooked up again when I can afford it as I have a propain fired water heater.

My propain dealer is another issue, the day my 30 gallon bradford white water heater failed they said that bradford whiel no longer makes the 30 gallon propain fired water heater; they lied about that and saddled me with a 40 gallon propain fired water heater for $3,000.00 too.

I will tell anyone that is looking to buy coal stoker boiler to not use them and set them aside and have an electrician wire in the honeywell units and a Bell & Gossett RB-122-E low water cut off switch as the hydrolevel units fail.

When the boiler controls failed the first time I was out of town taking care of my father and my wife called and said the house was full of steam and I told her to shut the power off to the boiler and get the animals out of the house and I was coming right home. I got home and the fortunately the stoker had run of out coal otherwise it would have had a steel failure.

Originally these boilers had the single honeywell aquastats to control them and they worked very well.

In my case as an example the second hydrolevel unit I was given failed; I was running the boiler on oil heat and as I was standing there watching the boiler temperature rise the low water cut off function turned itself off!!!!!!!!!!!!!!!!!!!!

SO I had that mess of chinese junk including the 4 inch round gauge replaced with the honeywell L8124L, the RB-122-E and a 4 inch Marsh Instruments triple gauge.

If I had purchased the VA400 I would still have it, and I would have been able to obtain parts and kept the AVCO LYCOMING boiler and the honeywell controls as well and saved a great deal of money in 44 years.

PC7060

Wow, quite a set of headaches but delta from $4k to $6k was a big hurdle back in ‘82 so I’m sure was reasonable choice at time.
my good friend is very experienced engineer likes to remind me “ good judgment comes from experience, experience comes from bad judgment”. 🫤

leonz

My experience with Alternate Heating Systems is just as crazy.

The AHS dealer who is no longer in business/passed away had Harmon coal stoker boilers and he hired a plumber out of Buffalo to come east to install them.

So as I was looking at coal stokers I drove up to Geneva, N.Y. twice to speak to the owner. The first time they were closed during the week and I explained to the man plowing snow that I drove a considerable distance almost 90 miles one way just to see one of these boilers and he said come back tomorrow.

SO I drove back home and drove back to their place west outside of Geneva, NY near the Ontario county border and I introduced myself and I asked the fellow if I could speak to someone about an AHS S130 Coal Gun.

Needless to say he was shocked when I asked this and he acted like I had just landed on earth from outer space and it went downhill from there; first clue.

I then said I understand that you sell AHS coal stoker boilers and he said yes, I just became an AHS Dealer because I could no longer sell Harman coal stokers; second clue

He went on to say I have never heard these boilers were referred to as coal gun boilers; third clue; I know nothing about them-fourth clue; I wanted to become and AHS stoker dealer since the Harman stokers were no longer available to me-fifth clue; and I have an AHS S130 down in the shed you can look at-sixth clue.

As it was, I could barely walk because my left knee was bone on bone and getting much worse, and the driveway down his shed was all ice.

The young man walked down to the shed and opened the door and turned the light on and There it was sitting on the shipping pallet complete with the standard direct drive induced combustion fans system, coal hopper, but no domestic coil and one ash drawer.

Now to the heart of the AHS S130:

The Coal Gun Boilers use a rolling fire grate system which is a copy of the Axeman Anderson 130S and 260S coal stoker boilers.

The pea or buck anthracite coal has to be loaded into the hopper by hand or by using a separate auger.

The AHS stoker boiler is designed to burn Buck or Pea Size Anthracite Coal using a gravity fed delivery system.

The induced draft combustion fan system comes in two types, the direct drive 110 volt AC motor which operates at 3,450 RPM or the Indirect Drive Belt driven combustion fan system which operates at 1750 RPM.

The direct drive induced combustion fan system is prone to dielectric corrosion where the the indirect V belt drive combustion fan system is not affected by dielectric corrosion as quickly due to the slow fan speed.

The induced draft fans for both models will suffer damage from the hot flue gasses that pass by the fan blades over time and the fans need to be replaced. At the same time it should be noted that the fan bearings will suffer damage from dielectric corrosion and should be replaced. The direct drive motors and bearings will become damaged and need to be replaced on occasion when the fans and fan sealing gasket is replaced as well.

The coal gas swirl chamber is mounted horizontally in the steam chest and the flue gasses are scrubbed of heat before they are pushed out of the 5 inch flue breech. The swirl chamber needs to be cleaned at least annually to assure that there is no buildup of fly ash in the swirl chamber.

The boiler base is not sealed and allows combustion air to enter the firebox from all four sides. The AHSS130 has 2 ash pit doors allowing the user to have access to the left or right side of the boiler to remove the ahs drawer.

The boiler base and combustion chamber are assembled as one unit.

I asked him how much the boiler was for a cash price-sixth clue; he said $7,000.00 and you have to hire your own plumber as I do not install stoker boilers -eighth clue.

He looked in the local phone book for a plumber and the only one that would install the boiler for you that I recommend is in Buffalo-nineth clue.

He provided me with a brochure and said I have customers waiting in the show room and walked away leaving me there wanting to ask more questions-tenth clue.

leonz

Bob, please forgive my ignorance but what is the BFD that you are referring to?

leonz

More on the VanWert and AHS coal stoker boilers;

Van Wert Manual Scan(2) (1).PDF

Van Wert Anthratherm - VA 400 - 600 - 800 - 110 - 150 - 190 (1) (2).pdf

vanwertcoalfeedrates.jpg

I am providing a link to youtube which shows a coal mine strip mine electrician from the State of Montana talking about his S130 Coal Stoker.

www.youtube.com/watch?v=pLvo3vJxgPs&t=5s

Coal-Gun-Manual-S130-S260_12225.pdf

hot_rod

https://forum.heatinghelp.com/discussion/comment/1906118#Comment_1906118

BFD is back flow device, this component.

By code, and common sense🤔the vent port needs to be piped down to the floor or near a drain.

They can spit from time to time if you get pressure variations upstream. With that valve off, less chance of a random spit.

leonz

Hello Bob,

Thank you for clarifying that for me. I am so used to calling it a back flow preventer it went right over my head.

My stoker has been working very well and in the last 9 hours has produced 5 pounds of ash.

My resetting the hold fire timer in 6 groups of 2 minutes on the 30 minute timer has worked well.

0-2 minutes, 5-7minutes, 10-12 minutes, 15-17 minutes, 20-22 minutes and then 25-27 minutes on the 30 minute timer.

The hold fire timer only activates the stoker if there is no heat call so in my case if there is no heat call 12 minutes out of every 30 will cause the stoker to run to maintain the coal fire.

I honestly think that my chimney being an 8 by 12 tile line chimney 16 feet tall is part of the problem requiring my adding pins to my hold fire timer each pin is equivalent to 15 seconds of operating time.

When I had the 3 foot stainless steel chimney extension on the chimney making it 19 feet tall the stokers draft/ negative pressure gradient was high and the fire was very high in the fire box.

If I had an 8 by 8 tile lined chimney 32+ feet tall the draft would be greater of course and my keystoker would not need the extended hold fire time to keep the stokers fire going. With a pot stoker it would not be an issue as the fire would be larger and the hold fire timer would only have to run 2 minutes every half hour.

Thank you Bob,

Leon

Robert_25

I honestly think that my chimney being an 8 by 12 tile line chimney 16 feet tall is part of the problem requiring my adding pins to my hold fire timer each pin is equivalent to 15 seconds of operating time.

It certainly isn't helping. How does the height of the chimney compare to surrounding structures?

Why didn't you turn the Keystoker 90 degrees and avoid the extra elbows in the fluepipe?

leonz

Good morning Robert_25,

The roof peak is slightly taller than the chimney; the surrounding conifers on both sides of the home and across the road at the Tilton farm house along with the willows and maple trees are almost 100 feet tall now and create the shelter belt that protects the home from high winds from the north and east.

There was not enough room to allow the boiler to be installed in a direct line with the chimney thimble to do this as an egress point would have been blocked.

Last year the flue pipe was replaced. The replacement flue pipe is set in this manner:

The first item is the removable flue baffle in the boiler, the flue baffles job is to hold the flue gasses as long as possible to allow the boilers wet wall which the flue breech passes through and the steam chest to capture as much heat as possible before it enters the flue breech and then the six inch tee.

The flue breech at the boiler is met with a 6 inch tee with a cap to allow the easy removal of fly ash that collects behind the removable flue baffle.

The next item is the short straight stove pipe set at about a 45 degree angle. The next item is a 45 degree adjustable elbow, after the 45 degree adjustable elbow a Tee holds the barometric damper and then the short flue pipe coupler allows the transition to a 90 degree adjustable elbow which meets the 6 inch to 7 inch reducer at the chimney thimble.

The new stove pipe is half as long as the original piping that used 2 fly ash traps. The new stove pipe arrangement is much easier to clean also.

leonz

I am happy to report that the stoker is making lots of heat and with the stoker mechanism at 12 threads out.

My changing the hold fire timer settings to create six 2 minute hold fires over thirty minutes has made all the difference in how the stoker operates and how little coal I am now burning.

It is not pushing a great deal of rice coal across the fire grate during a 2 minute hold fire AND the rice coal that is being burned is burned more slowly creating the fine light ash that I am seeing.

After a 24 hour burn period the 4.5 gallon ash bucket is not full of ash as the rice coal is being burned more slowly creating a light fluffy ash and I have a thick bed of dead ash on the end of the fire grate as tall as the side rails of the stoker.

The original stoker motor in the stoker now operates at 2 revolutions per minute, the new spare stoker I have operates at one revolution per minute and look forward to burning even less coal than I am now.

I just kick myself because of the coal I have wasted/lost in the last 11 years but there will be NO MORE wasting of coal with this coal stoker.

leonz

I checked my ash bucket this morning, and it only had one inch of coal ash in it after 10 hours of heating.

I weighed the ash that I had set aside before I put it out for collection last night and in 3 pails I had a total of 17 pounds of ash to put out for collection.

To say I am happy is an understatement, but if we have a heavy cold winter this will change.

The 30 minute Intermatic timer has become a better regulator of coal consumption for me as the two minute run time has reduce the time needed to make hot water and the summer settings of 140 Degrees Fahrenheit low limit and 160 degrees Fahrenheit high limit are well placed as the boiler quite often reaches 180 degrees Fahrenheit quickly and dumped at 190 degrees Fahrenheit back down to 180 degrees Fahrenheit low limit on the L6006L aquastat.

So anyway, my Intermatic 30-minute timer is set as follows.

O-2 minutes on

2-7 minutes off

7-10 minutes on

10-12 minutes off

12-15 minutes on

15-17 minutes off

17-20 minutes on

20-22 minutes off

25-27 minutes on

27-0 minutes off

The stoker timer will run to hold a fire is there is no heat call and the 3 minute periods when there is no fire the coal on the fire grate is still burning and will reignite the unburned coal being fed across the fire grate.

If there is a heat call the hold fire timer settings are bypassed until the heat call by the fire burning on the fire grate until the thermostat is satisfied.

I finally settled on these timer settings in six 2 minute hold fire periods because of my chimney and experimenting because the recommended timer settings will not keep a fire lit and results in an outfire.

My chimney is an 8 by 12 tile lined block chimney that is 16 feet tall and the peak of the house roof is 16 feet tall the chimney is too big and too short

I had a 3 foot stainless steel chimney extension installed 13 years ago because of down drafts and the pine trees surrounding my home and the Tilton farmhouse across the road are 100 feet all creating a huge shelter belt. blocking the prevailing winds and causing down drafts in my chimney which caused back puffing and St. Elmos fire in one instance and ball lightning that damaged my wife's office equipment.

The chimney extension increased the draft for the coal stoker and I used much more coal. The chimney extension had been blown off the chimney in a windstorm last year and I did not replace it.

If I had an 8 inch by 8 inch tile lined chimney 32 feet tall, the suggested normal settings would work well, but in saying that the new hold fire timer settings have reduced my coal use even more.

If I had stumbled on these new timer settings 10 years ago, I would have saved a great deal of coal and money and not wasted more coal for sure.

Part of the issue with burning anthracite coal is the fact that the State of Pennsylvania allows anthracite coal to have up to 13% rock in the delivered coal. If the coal breakers used a Bradford breaker as a primary crusher they would have a very small percentage of rock waste in their coal product of all sizes.

If these coal producers/breakers ran their coal product through the magnetite bath twice they would eliminate a great deal more of the rock in the rice, buck and pea coal sizes they sell.

If I had a VanWert VA400 or EFM DF520 pot stoker I would only have two 2 minute hold fire times per hour to maintain the fire in the burn pot but the fire in the Burn Pot/Tuyere underfed auger stokers is much larger in size.

I have been keeping track of my coal use and weighing my ash every week because my trash hauler whines about bag limits. I wanted to have a small dumpster for the winter but they were not at all cooperative about setting one for me.

I am hoping that if the UPRR/NS merger is approved the Sub Bituminous Coal mined in Wyoming will be here soon as it costs a great deal less per ton and has no rock in it. You would be burning more of it but the amount of ash is creates is so much less than anthracite coal. I would rather buy my heating coal for $100.00 a ton compared to $575.00 per ton for Anthracite rice coal and not being nailed by spot pricing. The Sub Bituminous Coal mined in Wyoming is being sold for $13.00-$16.00 per ton at the mine gate.

leonz

I woke up to a full 4.5 gallon ash bucket this morning after a 24 hour burn starting with an empty bucket.

I weighed the full bucket and it weighed 10.5 pounds, after subtracting the 3.5 pounds of tare weight for the bucket that leaves 7 pounds of ash and rock, GGRRR.

I guess I should plan on replacing the old 2 R.P.M. stoker motor with the new Koker stoker motor that operates at 1 revolution per minute to hopefully get a better burn, but the issue with rock in the coal is always a problem since the State of Pennsylvania allows the anthracite coal to have 13% rock in its weight per ton or 260+ pounds of slate/shale/mudstone/limestone waste rock in it.

leonz

29 October Update on my stoker boiler,

The honeywell L8124L triple aquastat was bad, we replaced it with a Honeywell L7224U digital triple aquastat, the plumber installed a new Watts LF9D2 back flow preventer.

I changed out the old circulator for a new NRF-25 last week and we now have plenty of heat.

leonz

Update on my KAA-4-1;

The Bell & Gossett circuit setter used as a boiler bypass is fully open and the Bell & Gossett NRF-25 circulator is set on speed one which is 12 gallons per minute.

I filled the coal hopper tonight and I only poured in 100 pounds of Anthracite Rice Coal.

I have not burned a lot of coal since Wednesday afternoon with the new hold fire timer settings, so far so good. I am very happy and I send a big shout out to HALCO heating and plumbing and James from HALCO who did the repair as a big thank you for the help.

😀😀

Leon