Keystoker Boiler Dump Zone Question

Stoker Coal Boilers automatically feed the coal and have controls and pumps just like any conventions boiler. They are intended to be used as a primary heat and often have domestic hot water coils as an added bonus. They can be set up independently or in dual sytem with your existing oil/gas boiler. They can accommodate both hot water base board or steam plumbing.
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stovepipemike
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Post Thu. Jan. 15, 2009 9:36 am

Here I sit working on my paper sketch of the boiler piping configuration [still no word on it from dealer or factory] and a question has come forward. Keystoker shows an aquastat in the feed pipe.I believe it is for a dump zone. What I would like to know are two pieces of information. #1 How many of us that have the keystoker boiler have seen a large [excessive] spike in temperature after a normal run? #2 How quickly will the fuel bed die off in a Kaa2 should the electric go off? Thanks for the information . Mike

Complete Heat
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Post Thu. Jan. 15, 2009 9:40 am

No major swings in the temps, and about 10-15 minutes for the fire to die. I had my dumpzone activate one time on the boiler at the store, and that was when the timer motor failed in the "on" position.

Mike
Heating with coal, driving with waste vegetable oil. Screw OPEC.

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stoker-man
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Hand Fed Coal Boiler: 1981 efm wcb-24 in use 365 days a year
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Post Thu. Jan. 15, 2009 11:18 am

On my efm installation I use a second aquastat (B) which activates the dump zone.
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LsFarm
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Post Fri. Jan. 16, 2009 12:27 am

Most coal burning stoker boiler owners on the forum do not use a dump zone, if you run the boiler temps at around 170*, you have 40*+ for temp overshoots.. with the exception of parts failures, I think most dump zones go unused in stoker boilers.

Now wood boilers, and hand feed coal boilers have less control over the heat output, and a dump zone is probably a good idea .

Greg L
Burning Pea/Buckwheat through an antique stoker [semi retired SSboiler],
Running an Axeman-Anderson 260M boiler burning Pea, About 150-250#per day
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ART52
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Stoker Coal Boiler: Keystorker KA22
Coal Size/Type: rice
Stove/Furnace Make: EFM--46years--now Keystoker
Stove/Furnace Model: KA2
Location: Jim Thorpe,Pa

Post Fri. Jan. 16, 2009 5:33 pm

Hello all :D
If anyone has a Keystoker KA2 it is a good idea to pull the pop off valve and let the air out of the top of the boiler. There is a sleeve welded on the boiler below the fitting where you take the heating water out. Why that sleeve is welded on there I do not know.
On the question of a bypass on a boiler. If a boiler does not have a bypass the water will not circulate inside the boiler it will lay in layers of different temperatures of water this goes for all boilers[ hot water boilers]
This comes from 50 years experience. :)
Donot run a KA2 with out a dump zone.
Art52

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Machinist
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Stoker Coal Boiler: Keystoker KAA-2
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Location: Telford, PA

Post Fri. Jan. 16, 2009 6:55 pm

My dump zone is just one of my heating zones.
It does dump heat now and then. I am still tweeking the feed rate.
Mike

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218Bee
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Post Fri. Jan. 16, 2009 8:58 pm

My KA-6 held fire for over two hours during a recent power outage. The juice came back on, the fire kicked back to life 8-)

No dump zone on my install, although I plumbed T's in for them. I have some finned copper that I was going to use, my buddy thought to be effective I would need a modine. That's definitely out of budget.
Rick

It was just my imagination
running away with me...

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stovepipemike
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Post Sun. Jan. 18, 2009 8:57 am

I appreciate having first hand information on the Kaa2 boiler. I think that their installation manual could be a bit more in depth,especially considering that it is a pressure vessel and not a mechanized garden tool.As an example,they say in their booklet that because of their experience the bypass loop should be installed, but not WHY it should be installed.Not even what can happen if it is not installed.Thanks for helping with the better picture of their boiler and it's behavior.

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AdkCoal
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Post Mon. Jan. 19, 2009 11:38 pm

Art52 said: If a boiler does not have a bypass the water will not circulate inside the boiler it will lay in layers of different temperatures of water this goes for all boilers[ hot water boilers]


Art52:

I am not trying to be a wise guy here, I am just trying to learn.

If a boiler has a bypass doesn't it only become activated when the boiler temp reaches the set level which in the case of a KA2 is supposed to be 200* according to the manual. If the bypass is not active then would not your layering effect be taking place anyway?

I did not install the bypass on my KAA-2 and to my knowledge it has not over fired yet but there is always the possibility.

I am considering installing a bypass this spring once I shut the unit down just to be on the safe side.

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218Bee
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Post Wed. Jan. 21, 2009 12:41 pm

I did not stay at a Holiday Inn last Night ( you have been warned).

So there's no confusion, I installed the bypass loop (balancing loop) but not a dump zone. The bypass loop, as I understand it, can be used to raised the internal tempurature of the boiler by returning water to the supply line directly from the return line, bypassing the boiler vessel. The higher boiler temperature ensures adequately hot DHW from the boiler coil. At the time of my install, I figured a few extra feet of pipe and a couple of valves were within the budget and I'd was already fitting pipe. I also would rather not need it and have it. I don't use the hot water coil, keep the loop closed and haven't had to mess with it.

The dump zone is a differnet animal entirely although the controler for the dump zone sits in a well on the balance loop, as shown in the instruction manual (such as it is). It needs to be wired to a circ pump on a dump zone, which would activate in a high temprature situation.

Hopefully the old hands here will correct me if I'm wrong. Not that thats ever happened :cry:
Rick

It was just my imagination
running away with me...

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