Dump Zone for EFM520

stoker-man wrote:

You probably wouldn't get away with 160/180 in the Winter either

I wasn't clear enough. I was commenting on what AA130FIREMAN said about his AA and meaning that he probably would have trouble with the 520 even in the Winter at such close settings.

Yes you were not clear as what you were stating the AA or 520 AA yes 520 no that would go for any under fed stoker boiler and for most if not all of the flat bed stokers or incline stoker boilers you need a bigger spread between the low & high set point temp on the Aquastat 20 degrees difference real don't work in most boilers 30 to 40 degrees sometime it
takes a 50 degrees span to make them happy.

AA is a big hand fed like boiler but with a auto feed & ashing feeds the coal from top and ashes from bottom with the fan on the other end pulling the fire up out of the fire chamber and across the the water jacket inside boiler then the exhaust leaves the top of boiler

I don't know much on the wireing on the EFM,is the high and low on a triple aquastat ? My AA uses a triple aquastat that runs the blower motor. The high limit on the triple stops the blower/auger and asher on a common motor. Their is an aquastat that is a high limit cutoff to the motor between the triple and motor. My timer bypasses the triple but does not bypass the high limit cutoff ( I keep it at 190-195 ) and the dump zone is set at 200.
The triple aquastat also controlls the circulator pump (or should in most cases), if the water temp. is at the low limit the circulator will not run. With mine set at 160 the circulators cut out at 155-158
I know their must be a difference of 20 between the high and low to keep it from jumping between the 2 and wanting to run all the time. I don't have any issues with that. Guess the AA just has a bigger bed of coal .

You may have a hard time finding a strap on aquastat (at least a Honeywell) with a high greater that 200, when I looked for mine, that was all I could find. So I am peged on the max on that one, unless someone has a part # for something higher. Their is always eBay

Look up Honeywell L4006

AA130FIREMAN wrote:You may have a hard time finding a strap on aquastat (at least a Honeywell) with a high greater that 200, when I looked for mine, that was all I could find. So I am peged on the max on that one, unless someone has a part # for something higher. Their is always eBay

The Honeywell L8124 triple Aquastat will go to 240F High Now if you have the high limit set for 200f with a 10diff or what ever you are running the diff at and if the boiler temp is at 200f or above the diff range The Aquastat will not leave the Timer to kick on until the temp drops below the high set point or below the diff setting . The Aquastat will override the timer stopping it from cycling until the boiler water temp drops back which can cause a out fire in a EFM . That's why you need a 30 to 50 degree span between the low & high set point on Aquastat in Summertime & in some cases running the timer every hr instead of every 30 minutes to prevent the water temp from hitting the high set point All depends what the DHW consumption is that your using Thur out the day or night These boilers will hold the water temps all day long if the water is not being used meaning new fresh cooler water coming in to Thur water coil cooling / lowering down the boiler water temp. coal consumption will be less when timer fires on every hr instead of every 30 minutes but some peoples setups & brand/type of coal will not allow that some need to stay on every 30 minutes .

coal berner wrote:

AA130FIREMAN wrote:You may have a hard time finding a strap on aquastat (at least a Honeywell) with a high greater that 200, when I looked for mine, that was all I could find. So I am peged on the max on that one, unless someone has a part # for something higher. Their is always eBay

The Honeywell L8124 triple Aquastat will go to 240F High Now if you have the high limit set for 200f with a 10diff or what ever you are running the diff at and if the boiler temp is at 200f or above the diff range The Aquastat will not leave the Timer to kick on until the temp drops below the high set point or below the diff setting . The Aquastat will override the timer stopping it from cycling until the boiler water temp drops back which can cause a out fire in a EFM . That's why you need a 30 to 50 degree span between the low & high set point on Aquastat in Summertime & in some cases running the timer every hr instead of every 30 minutes to prevent the water temp from hitting the high set point All depends what the DHW consumption is that your using Thur out the day or night These boilers will hold the water temps all day long if the water is not being used meaning new fresh cooler water coming in to Thur water coil cooling / lowering down the boiler water temp. coal consumption will be less when timer fires on every hr instead of every 30 minutes but some peoples setups & brand/type of coal will not allow that some need to stay on every 30 minutes .

I was referring to the strap on type of aquastat that would be used to controll the dump zone Seems like the conversation wend on a different road I use a honeywell l6006 c 1018 that is 200 as the high, contacts make on rise. I did look at others, but did not see any that were STRAP ON, only well emmersion, but they have a higher limit 240.

AA130FIREMAN wrote:

coal berner wrote:

AA130FIREMAN wrote:You may have a hard time finding a strap on aquastat (at least a Honeywell) with a high greater that 200, when I looked for mine, that was all I could find. So I am peged on the max on that one, unless someone has a part # for something higher. Their is always eBay

The Honeywell L8124 triple Aquastat will go to 240F High Now if you have the high limit set for 200f with a 10diff or what ever you are running the diff at and if the boiler temp is at 200f or above the diff range The Aquastat will not leave the Timer to kick on until the temp drops below the high set point or below the diff setting . The Aquastat will override the timer stopping it from cycling until the boiler water temp drops back which can cause a out fire in a EFM . That's why you need a 30 to 50 degree span between the low & high set point on Aquastat in Summertime & in some cases running the timer every hr instead of every 30 minutes to prevent the water temp from hitting the high set point All depends what the DHW consumption is that your using Thur out the day or night These boilers will hold the water temps all day long if the water is not being used meaning new fresh cooler water coming in to Thur water coil cooling / lowering down the boiler water temp. coal consumption will be less when timer fires on every hr instead of every 30 minutes but some peoples setups & brand/type of coal will not allow that some need to stay on every 30 minutes .

I was referring to the strap on type of aquastat that would be used to controll the dump zone Seems like the conversation wend on a different road I use a Honeywell l6006 c 1018 that is 200 as the high, contacts make on rise. I did look at others, but did not see any that were STRAP ON, only well immersion, but they have a higher limit 240.

6006 well immersion or strap it on 4006-1004 strap on and well immersion.

http://customer.honeywell.com/honeywell ... L4006H1004

http://customer.honeywell.com/Honeywell ... 218DD64%7d

http://customer.honeywell.com/Honeywell ... 218DD64%7d

You can also tape the bulb to any pipe and insulate it with black foam and use any aquastat, A or C, to achieve this task. As long as the bulb is tight against the pipe.