Decision Between Keystoker and AHS Coal Gun

I'm a newbee and have done a lot of looking around at the many different stokers. I've narrowed it down between 2 ,the Keystoker KA-6 and the AHS coal gun S-130. The Keystoker has a bottom stack vent which is a good point that keep most of the heat in the boiler but the only thing that concerns me is how much fly ash is produced. I'm told I have to clean that out if I used the oil burner option. The second thing that is a concern is the plastic parts in the feed mechanism that could melt as I've read on this forum which would leave the back up oil option. They also said the boiler is fully insulated which give you the option to burn coal in the summer and not heat up basement. Whereas the AHS 130 eliminates fly ash by design and put it in the ash bin but it is not insulated and would heat up the basement. And there are differences in height the AHS will be somewhere around 5ft and the Keystoker is 42 inches which is much lower, my basement is 6ft to rafters are 6ft and pipes for heating hang another foot down. Sorry for the long letter but as you know is a big investment and you can't give it back if you don't like it and there's the wife . So any help!!!!!! will be greatly appreciated.

I don't have a lot to add except that the KA-6 Keystoker stoker mechanism has no plastic parts like the KAA-2 unit and the stoves (which use a similar design). The KA-4 and larger units have the "old school" stoker mechanism which is far more robust and very simple.

I have a Keystoker stove, so I'm partial to them. I'd get the KA-6 in a heartbeat.

Chris

I believe the AA/AHS boiler design and the fan-forced heat exchanger are more effecient at passing heat into the water than the heat exchanger in the Keystoker design.

The flat bed stoker mechanism is easier to see what is going on with the fire, the coal, and the feed. The AHS/AA firepot is fully enclosed and can hide burning issues..

The deciding factor is that the AHS has the coal hopper up above the boiler, and would be a pretty tight fit for loading the hopper every few days to a week. You need to make a mock-up of the hopper and see if you can or want to be filling the hopper that is that close to the ceiling/floor joists.

From the standpoint of heatexchanger effeciency and coal use, I'd lean towards the AHS.. But for ease of sorting out burning issues, and feeding the boiler fuel, I'd lean towards the Keystoker.

Now if you can find a good used AA or Eshland 130 boiler... I'd lean that way, they use a floor level coal hopper and an auger feed to the top of the boiler.

Greg L

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LsFarm wrote:I believe the AA/AHS boiler design and the fan-forced heat exchanger are more effecient at passing heat into the water than the heat exchanger in the Keystoker design.

No question about it, get the AHS.

My cent and a half would be, well it's up to you. I looked long and hard at the AHS and Axeman-Anderson, really wanted an EFM 520 but bought a used KA-6 and am very happy with it ever since. A few growing pains of my own doing but she is running trouble free now. I still say the most important things about a coal stoker are good coal, proper installation, and proper setup ie. adjusted properly to spec.

The Keystoker is mechanically very simple and I could see the stoker mechanism running for 100 years without wearing out. It is slow moving and just a couple of pieces moving. The weakest link may be the $60 Fasco secondary blower which is a late addition to the design. However this blower could die and it would not greatly affect performance nine months out of the year. They do create a good amount of fly ash that must be periodically removed from the stack and insides of the boiler. Strong points would be initial cost and simple design, it should never break down.

The AHS is like the Axeman Anderson in many ways with what are considered a few improvements. It is my understanding they more or less self clean, they no doubt get more BTUs out of a pound of coal than the Keystoker. They are more mechanical than the Keystoker and I have no Idea what the reliability of the moving parts is. The potential for more breakdowns and costly breakdowns is there but it is just a potential. The AHS owners on the forum will have to let us know if there are any issues like this.

In the end the AHS would not have fit in my basement because I have a low basement too. The man who built the house a hundred years ago got tired of digging when he hit rock and I got tired just thinking of digging another foot or two through rock. Also the price trumped everything else. New boilers are not cheap and if you find a good used one, any make as long as parts are available, that will be your best bargain.

No matter what you end up with in the end you will be happy when you see how many dollars you save in a year.

my 1/2 cent

gaw is right . I think any stoker would be great. burn good coal and have a good set up and you are good. I own a ahs130 with the optional belt drive fan and electronic control. this is a very simple machine with these options as compared to a regular AA. I ony have 2 motors one is a belt drive for fan and the other is the chain drive for the grate which hooks to a rod to drag the grate back and fourth. plus a hopper. very very simple. the thermal couple lets you know whats happening with your fire . makes it very easy to start a coal fire. but if you have low ceiling this may not be a option. unless you go with a smaller hopper and augar. you would have to talk to jeff at ahs about hooking this up. good luck stay warm

Get an Axeman which uses the stoker tube. My basement is about 7 ft tall and my bin hold 4 tons of pea when absolutely full. Axemans are fool proof.

I looked at the Axeman and it's another $1000.00 more than AHS and $2000.00 more than the Keystoker. I missed a AHS 130 for $1700.00 last weekend by 12 hours

BillMarti wrote:I looked at the Axeman and it's another $1000.00 more

Money well spent though.

Don't be afraid of a used AA unit. The most common issues are a burnout of the the inner bottom lip of the fire chamber (caused by long term over firing), seized rollers on the grate and wearing away of the end of the coal tube. All are an easy fix. The early controls are unusual and out of production, but the new controls are simple and off the shelf Honeywell items.

i installed a keystoker kaa-2 and I am very happy with it.i guess you cant go wrong with any of the coal boilers they all seem quality built and american made just depends what you want to spend

chris

I put in a keystoker kaa-2 in December. We hooked it up as a slave unit to my current propane boiler. keeps the house warm, uses 2 bags a day. Have had problems keeping the water hot. maybe I'm just used to having to keep the propane unit at 190 to keep the house 68. We now keep it at 72. The controls don't appear to be compatible with the zone valves. we decided to let the hi lo limit on the keystoker control the fire and the thermostats in the house control the pump. By the way, we spent 3600 on propane last year.

hello boiler man I sent you an e-mail about your boiler controls

let me know chris

1975gt750 wrote:i guess you cant go wrong with any of the coal boilers they all seem quality built and american made just depends what you want to spend

That is a good summation.

I've got the AHS boiler and I'm very happy with it. As many have said almost all coal boilers will do the job and it comes down price making the purchasing decision. In my opinion the AHS boiler is superior to the A-A boiler. The two motor design, one for the combustion blower and one for the grate allows independent control more easily with electrical switches rather than a mechanical cam. The AHS boiler with the hopper is a derivative of the Eshland boiler which like the A-A did have a helicoid auger. I guess the hopper design was a way to lower the cost. AHS told me they would sell a helicoid flighting auger for their boiler, but they don't recommend it because a standard screw auger design is less expensive. Again in my opinion the 4 inch pipe thread domestic water coil in the AHS is superior to the flat plate seal type in the A-A.

For someone buying new and on a budget I would recommend an AHS with the grate timer and a hopper purchased during the summer sale price. It will work well and you will be happy with it. As finances permit the thermocouple control can be added. Prices for a non-Fuji brand PID controller are considerably less expensive and will work equally well. In fact they are more universal. To save money I would not purchase the domestic coil, but would add, when finances permit, an indirect hot water heater or external heat exchanger and a conventional hot water heater.