Short Cycling

Short Cycling

PostBy: johnniecuse On: Tue Jan 31, 2012 9:05 pm

Does anyone have an issue with the LL 110K short cycling. I am getting great heat out of the boiler. But I have noticed that sometimes when all zones are satisfied and the boiler goes into the idle mode, it fires back up within a minute ore two. My set points are as follows:

Low limit - 160
High limit - 180
PRV Aquastat - 180

The Aquastat to in the DHW loop is set to 130.
Today the house was satisfied and the boiler temp was 171F. The boiler went into idle then fired back up within a minute.

Also, I do not have a dump zone piped in yet.

Pictures of my install are attached.
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johnniecuse
 
Stoker Coal Boiler: Leisure Line 110K Boiler
Coal Size/Type: Rice

Re: Short Cycling

PostBy: Rob R. On: Tue Jan 31, 2012 9:30 pm

The stoker may have fired on a timer cycle. My EFM does the same thing on occasion...the timer has no way to know if the stoker was just running.
Rob R.
 
Stoker Coal Boiler: EFM DF520
Hand Fed Coal Stove: Hitzer 50-93
Other Heating: Dad's 1953 EFM Highboy

Re: Short Cycling

PostBy: coaledsweat On: Tue Jan 31, 2012 9:52 pm

Or it may just be that during a temperature fall from the hi limit setting once the differential is met that the boiler fires on a call for heat. When it does it, I'll bet the pump is running. Once the zone is satisfied the boiler will quit firing.
coaledsweat
 
Stoker Coal Boiler: Axeman Anderson 260M
Coal Size/Type: Pea

Visit Leisure Line Stove

Re: Short Cycling

PostBy: stoker_RI On: Tue Jan 31, 2012 11:11 pm

What do you have your idle settings adjusted to?
stoker_RI
 
Stove/Furnace Make: Leisure Line
Stove/Furnace Model: WL 110 Boiler

Re: Short Cycling

PostBy: plumber On: Thu Feb 02, 2012 7:44 am

Rob R. wrote:The stoker may have fired on a timer cycle. My EFM does the same thing on occasion...the timer has no way to know if the stoker was just running.

The timer that Liesure Line uses does, and resets if the burner circuit calls. At least that is the way my boiler came wired.
plumber
 
Stoker Coal Boiler: EFM 350

Re: Short Cycling

PostBy: plumber On: Thu Feb 02, 2012 7:46 am

coaledsweat wrote:Or it may just be that during a temperature fall from the hi limit setting once the differential is met that the boiler fires on a call for heat. When it does it, I'll bet the pump is running. Once the zone is satisfied the boiler will quit firing.


I agree, I've noticed that with my boiler as well. Same when I had oil.

PRV aquastat?
plumber
 
Stoker Coal Boiler: EFM 350

Re: Short Cycling

PostBy: stoker_RI On: Thu Feb 02, 2012 10:03 am

Ditto Plumber...as long as there is demand, once the temp falls the 10 degree differential from the HL setting, the boiler will fire..the dif setting is fixed at 10*..a user can not alter it...once the demand is met, off goes the boiler and circulator...unless, of course, for some strange reason your temps free fell to below the LL too, and then the boiler would continue to fire until temps rose to the LL, but the pump would be off..
stoker_RI
 
Stove/Furnace Make: Leisure Line
Stove/Furnace Model: WL 110 Boiler

Re: Short Cycling

PostBy: coaledsweat On: Thu Feb 02, 2012 11:44 am

stoker_RI wrote:unless, of course, for some strange reason your temps free fell to below the LL too, and then the boiler would continue to fire until temps rose to the LL, but the pump would be off..

Once it reaches the LL it should run until it hits the HL I would think.
coaledsweat
 
Stoker Coal Boiler: Axeman Anderson 260M
Coal Size/Type: Pea

Re: Short Cycling

PostBy: stoker_RI On: Thu Feb 02, 2012 1:52 pm

coaledsweat wrote:
stoker_RI wrote:unless, of course, for some strange reason your temps free fell to below the LL too, and then the boiler would continue to fire until temps rose to the LL, but the pump would be off..

Once it reaches the LL it should run until it hits the HL I would think.


Thats true only if a demand still exists..otherwise, if the demand is satisfied, and the water temp is below LL-dif, the boiler will run until the water temp is up to the LL and then shut off...at least thats how this HW7224 control works..can't vouch for earlier of different brand controls...
stoker_RI
 
Stove/Furnace Make: Leisure Line
Stove/Furnace Model: WL 110 Boiler

Re: Short Cycling

PostBy: coaledsweat On: Thu Feb 02, 2012 3:10 pm

stoker_RI wrote:Thats true only if a demand still exists..otherwise, if the demand is satisfied, and the water temp is below LL-dif, the boiler will run until the water temp is up to the LL and then shut off...at least thats how this HW7224 control works..can't vouch for earlier of different brand controls...

That's not what is described here.

http://www.forwardthinking.honeywell.co ... 9_1957.pdf
coaledsweat
 
Stoker Coal Boiler: Axeman Anderson 260M
Coal Size/Type: Pea

Re: Short Cycling

PostBy: stoker_RI On: Thu Feb 02, 2012 5:19 pm

The 'flavor' of the control that comes with the boiler is the HW L7224C.... The information that you are referring to may be valid for the L7224U...

Please see pages 6 and 8 of the following...this *.pdf is posted right on the Leisure Line web site as documentation for the aquastat used on the boiler...

HW L7224c.pdf
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stoker_RI
 
Stove/Furnace Make: Leisure Line
Stove/Furnace Model: WL 110 Boiler

Re: Short Cycling

PostBy: coaledsweat On: Thu Feb 02, 2012 5:50 pm

I see now. First one I've seen with dual differentials. Very interesting.
coaledsweat
 
Stoker Coal Boiler: Axeman Anderson 260M
Coal Size/Type: Pea

Re: Short Cycling

PostBy: stoker_RI On: Thu Feb 02, 2012 9:45 pm

Honey well literature can be a pain! Yes..there is an abundance of literature available from them, yet its easy to walk away from it scratching your head sometimes....they found a way to never quite be concise, it seems!
stoker_RI
 
Stove/Furnace Make: Leisure Line
Stove/Furnace Model: WL 110 Boiler

Visit Leisure Line Stove