Stoker Boiler Operating and Temperature Controls

 
lzaharis
Member
Posts: 2358
Joined: Sun. Mar. 25, 2007 8:41 pm
Location: Ithaca, New York
Stoker Coal Boiler: Keystoker KAA-4-1 dual fuel boiler
Hand Fed Coal Boiler: former switzer CWW100-sold
Coal Size/Type: rice
Other Heating: kerosene for dual fuel Keystoker/unused

Post by lzaharis » Thu. Mar. 02, 2023 9:34 am

Hello Bernie,

Your radiators will always become cold between calls for heat as the heat delivered
by the hot water is stored in the radiators water chambers and absorbed by the metal
in the radiator sections by convection and shed into the room.

The heat absorbed by the metal in each radiator section is being shed by the radiator
into the room at all times until the thermostat senses that the temperature has dropped
below the desired setting for the home. This is referred to as electromagnetic radiation
which is exactly how the sun heats you or a room full of windows or your dog or cat laying
in a sun beam and how the heat in a radiators rises upward and outward to the ceiling if it
is not covered by a radiator cover.

The combination of the heat in the water and the heat absorbed by the cast iron or steel
radiator and the piping that connects the radiator to the heating system is referred to as
thermal mass.

Your radiators work by radiating heat into the living space using convection to transfer this
heat in the water to the steel or cast iron in your radiators which then sheds this heat into
the rooms.

Rather than reverse engineering a broken triple aquastat it is more important to understand
that the thermocouple that is in the dry well the boilers steam chest controls the low limit
temperature, high limit temperature and the differential temperature of your boiler that also
activates the circulator to shed the excess temperature created by the boiler to protect the
heating system from overheating. The pop off valve is the last line of defense for your heating
system to prevent an overpressure condition i n your boilers steam chest to prevent it from
rupturing in the event the water pressure reaches 30 Pounds per Square Inch Gauge pressure.

I have been there and done that with the digital triple aquastats which I got rid of.

Raise the low limit on your L8124A 10 degrees to 150 Degrees Fahrenheit and the High limit
to 170 Degrees Fahrenheit and leave the differential temperature set at 10 Degrees Fahrenheit.
And you will have plenty of heat.

 
Bernie
New Member
Posts: 7
Joined: Tue. Feb. 21, 2023 6:06 pm
Location: Tremont Township PA
Stoker Coal Boiler: EFM 700 furnace with a EMF 530 stoker
Coal Size/Type: Rice / Anthracite
Other Heating: Propane fireplace

Post by Bernie » Thu. Mar. 02, 2023 11:27 pm

Hi Lzaharis

Thanks for the reply greatly appreciated. When we purchased this house last September the furnace was in bad shape. We had an EFM service personnel come in and get the system up and running. My son and I were basically clueless about coal furnaces. We are learning fast reading every thing we can find on line. Coalpail.com has been priceless with all of the information posted here. The manufacturer info on line is also a great help. Since reading this thread I now understand the L8124A better but I still want one to reverse engineer it. Example the blue where is it connected and how does the differential thing work.

Things we have already corrected:
Moved the thermostat from the uninsulated cellar stairwell wall to an inside wall..

The two heat registers in the kitchen dinning room did not produce heat . The ball valve in the return line was broken open and we could not bleed the air from the line. Replaced the valve still no heat from the registers. We are now installing a new circulator pump in the line. The registers produce heat in the kitchen dining room.

The timer was not connected to the ZR terminal in the L8124A therefore it did no control the furnace. Moved the wire to the ZR terminal. Timer now controls the furnace.

The radiators in my bedroom above the furnace never really cooled down. They were hot/warm 24/7. The temperature in the room could easily reach 76 deg. The stoker was feeding the furnace at more than 14 teeth each time it ran. The furnace was running 190/200 deg constantly. After reading this thread and getting a better understanding of the differential part of the Qustat we were able to reduce the teeth to 7 each time the furnace runs. I am sure we will be able to reduce it further. The furnace is now running at about 170/180.

So that’s where we are now and hope to get the furnace fine tuned and running well..

Thanks for the advice
Bernie

 
User avatar
Retro_Origin
Member
Posts: 900
Joined: Sun. Feb. 21, 2021 7:46 pm
Location: Schuylkill county
Stoker Coal Boiler: 1957 Axeman Anderson 130
Coal Size/Type: Buckwheat / Pea

Post by Retro_Origin » Fri. Mar. 03, 2023 7:19 am

Bernie wrote:
Thu. Mar. 02, 2023 11:27 pm
Hi Lzaharis

Thanks for the reply greatly appreciated. When we purchased this house last September the furnace was in bad shape. We had an EFM service personnel come in and get the system up and running. My son and I were basically clueless about coal furnaces. We are learning fast reading every thing we can find on line. Coalpail.com has been priceless with all of the information posted here. The manufacturer info on line is also a great help. Since reading this thread I now understand the L8124A better but I still want one to reverse engineer it. Example the blue where is it connected and how does the differential thing work.

Things we have already corrected:
Moved the thermostat from the uninsulated cellar stairwell wall to an inside wall..

The two heat registers in the kitchen dinning room did not produce heat . The ball valve in the return line was broken open and we could not bleed the air from the line. Replaced the valve still no heat from the registers. We are now installing a new circulator pump in the line. The registers produce heat in the kitchen dining room.

The timer was not connected to the ZR terminal in the L8124A therefore it did no control the furnace. Moved the wire to the ZR terminal. Timer now controls the furnace.

The radiators in my bedroom above the furnace never really cooled down. They were hot/warm 24/7. The temperature in the room could easily reach 76 deg. The stoker was feeding the furnace at more than 14 teeth each time it ran. The furnace was running 190/200 deg constantly. After reading this thread and getting a better understanding of the differential part of the Qustat we were able to reduce the teeth to 7 each time the furnace runs. I am sure we will be able to reduce it further. The furnace is now running at about 170/180.

So that’s where we are now and hope to get the furnace fine tuned and running well..

Thanks for the advice
Bernie
I'm right over the hill from you in valley view if you want to buy an aquastat to fiddle with I have an extra one, send me a pm and we can work it out

 
lzaharis
Member
Posts: 2358
Joined: Sun. Mar. 25, 2007 8:41 pm
Location: Ithaca, New York
Stoker Coal Boiler: Keystoker KAA-4-1 dual fuel boiler
Hand Fed Coal Boiler: former switzer CWW100-sold
Coal Size/Type: rice
Other Heating: kerosene for dual fuel Keystoker/unused

Post by lzaharis » Fri. Mar. 03, 2023 10:26 am

Bernie wrote:
Thu. Mar. 02, 2023 11:27 pm
Hi Lzaharis

Thanks for the reply greatly appreciated. When we purchased this house last September the furnace was in bad shape. We had an EFM service personnel come in and get the system up and running. My son and I were basically clueless about coal furnaces. We are learning fast reading every thing we can find on line. Coalpail.com has been priceless with all of the information posted here. The manufacturer info on line is also a great help. Since reading this thread I now understand the L8124A better but I still want one to reverse engineer it. Example the blue where is it connected and how does the differential thing work.

Things we have already corrected:
Moved the thermostat from the uninsulated cellar stairwell wall to an inside wall..

The two heat registers in the kitchen dinning room did not produce heat . The ball valve in the return line was broken open and we could not bleed the air from the line. Replaced the valve still no heat from the registers. We are now installing a new circulator pump in the line. The registers produce heat in the kitchen dining room.

The timer was not connected to the ZR terminal in the L8124A therefore it did no control the furnace. Moved the wire to the ZR terminal. Timer now controls the furnace.

The radiators in my bedroom above the furnace never really cooled down. They were hot/warm 24/7. The temperature in the room could easily reach 76 deg. The stoker was feeding the furnace at more than 14 teeth each time it ran. The furnace was running 190/200 deg constantly. After reading this thread and getting a better understanding of the differential part of the Qustat we were able to reduce the teeth to 7 each time the furnace runs. I am sure we will be able to reduce it further. The furnace is now running at about 170/180.

So that’s where we are now and hope to get the furnace fine tuned and running well..

Thanks for the advice
Bernie


====================================================================================================


Hello Berine,

Please clarify this; do you mean the low limit is 170 Degrees Fahrenheit and
the High Limit Temperature is 180 Degrees Fahrenheit??
Last edited by lzaharis on Fri. Mar. 03, 2023 11:01 am, edited 1 time in total.


 
User avatar
Rob R.
Site Moderator
Posts: 17965
Joined: Fri. Dec. 28, 2007 4:26 pm
Location: Chazy, NY
Stoker Coal Boiler: EFM 520
Hand Fed Coal Stove: Chubby Jr

Post by Rob R. » Fri. Mar. 03, 2023 10:30 am

You may find the EFM 900 manual useful.

http://cdn.efmheating.com/Boiler-Stoker-Manual.pdf

 
Bernie
New Member
Posts: 7
Joined: Tue. Feb. 21, 2023 6:06 pm
Location: Tremont Township PA
Stoker Coal Boiler: EFM 700 furnace with a EMF 530 stoker
Coal Size/Type: Rice / Anthracite
Other Heating: Propane fireplace

Post by Bernie » Fri. Mar. 03, 2023 11:04 am

Hi Izaharis

I was referring to the temp of the boiler. 170/180 deg.

My limits are set to LO 140 HI 190 and DIF of 10.

Bernie

Hi Rob R.

Yes I have the EFM 900 pdf already. I also have the original EFM 700 manuals that came with the furnace in 1964. LoL they were pretty dusty. I PDFd them so I would have them..

Thanks
Bernie

 
User avatar
Rob R.
Site Moderator
Posts: 17965
Joined: Fri. Dec. 28, 2007 4:26 pm
Location: Chazy, NY
Stoker Coal Boiler: EFM 520
Hand Fed Coal Stove: Chubby Jr

Post by Rob R. » Fri. Mar. 03, 2023 11:06 am

Bernie, could you please post the EFM 700 manuals?

I have never seen a complete set and would save them in case anyone else needs one.

 
Bernie
New Member
Posts: 7
Joined: Tue. Feb. 21, 2023 6:06 pm
Location: Tremont Township PA
Stoker Coal Boiler: EFM 700 furnace with a EMF 530 stoker
Coal Size/Type: Rice / Anthracite
Other Heating: Propane fireplace

Post by Bernie » Fri. Mar. 03, 2023 11:18 am

Hi Rob R.

No problem. It will take me a day or two..

I am wiring the new kitchen circulator pump into the system today..

Bernie


 
User avatar
Rob R.
Site Moderator
Posts: 17965
Joined: Fri. Dec. 28, 2007 4:26 pm
Location: Chazy, NY
Stoker Coal Boiler: EFM 520
Hand Fed Coal Stove: Chubby Jr

Post by Rob R. » Fri. Mar. 03, 2023 11:20 am

Bernie wrote:
Fri. Mar. 03, 2023 11:18 am
Hi Rob R.

No problem. It will take me a day or two..

I am wiring the new kitchen circulator pump into the system today..

Bernie
Thank you. Let us know if you have any other questions

 
RICHARD2
Member
Posts: 38
Joined: Sun. May. 04, 2008 1:34 pm
Location: Upstate New York
Stoker Coal Boiler: EFM

Post by RICHARD2 » Thu. Mar. 23, 2023 3:19 pm

Bernie wrote:
Thu. Mar. 02, 2023 12:08 am

BTW I am interested in getting my hands on a L8124A (even a broken one).. I want to reverse engineer it and make a complete schematic to include the differential control..
Honeywell provides a schematic of the internal wiring; and a chart showing the suffix letter differences between the 8124 controls; and a graphic explaining the relationship of the low, high and differential settings. see pages 1, 3 and 7 on this link:

https://www.manualslib.com/manual/526976/Honeywel ... tml#manual

 
Bernie
New Member
Posts: 7
Joined: Tue. Feb. 21, 2023 6:06 pm
Location: Tremont Township PA
Stoker Coal Boiler: EFM 700 furnace with a EMF 530 stoker
Coal Size/Type: Rice / Anthracite
Other Heating: Propane fireplace

Post by Bernie » Thu. Mar. 23, 2023 9:55 pm

Hi Richard2

Thank you for that information.. I have that information and also the product data sheet located at https://www.manualslib.com/manual/1611558/Honeywe ... T%20L8124A

Neither manual shows the blue wire on the schematic and not much information about its use. For that reason and also the fact that that I wanted to understand exactly how the LO-HI-DIF works. My control seems to turn off the circ pump a few minutes after the thermostat calls for heat and this seems to happen regardless of boiler temperature.

I have learned a lot since my original post and my EFM furnace is working very well now. I can’t wait for summer to see how well it works making hot water and no heat. Ha Ha…

Thanks again
Bernie.

Post Reply

Return to “Stoker Coal Boilers Using Anthracite (Hydronic & Steam)”