AHS Coal Gun: Thermo Ash Grate Control question

For those of you with Coal Guns that are equipped with the thermo ash grate control system, what have you found to be the best temperature setting value for set-point S.V.?

Mine came factory pre-set at 140 degrees, but the manual says to set it at 130 degrees (and to never set it lower than 120 degrees). Does it save on coal if set to a lower temperature? I'm assuming that if it is set too low the potential for an out-fire is increased, but the lower it is set, the less likelihood of unburned coal going into the ash pan. Is this a correct assumption?

I can't answer your questions other than to say my buddy has his set at 130 & leaves it there. He's happy, it's happy.

PS... if you shut the asher while you're emptying the ashes, make some way to remind yourself... a red flag,a timer, something. If you forget to turn the asher back on, bad things start to happen.... such as, the fire burns up into the hopper. Charlie has the burned paint to remind him of the lesson.

Freddy, thanks for those words of caution!!! So far I've been able to tell that the ash grate motor is not near running just by looking at the differential between the grate temperature and the set-point, so under those circumstances I have not turned off the grate switch when removing the ash pan for emptying.

I just dropped my set-point down to 130 degrees and locked it in.

during the summer i was running the aquastat at lowest 135 and sv at 109.
currently 50F and i'm running 145 and sv at 120. The water temp goes between 160-180.

This thing is a monster its keeping my 1st floor at 75 just from basement radianting. Currenntly 1st floor air handler is off. Having to open window stats.

130 has worked for me, no out fires no puff backs and not much unburnt coal. I have not changed the sv from 130. If it ain't broke don't fix it.
Randy

lsayre wrote:For those of you with Coal Guns that are equipped with the thermo ash grate control system, what have you found to be the best temperature setting value for set-point S.V.?

Mine came factory pre-set at 140 degrees, but the manual says to set it at 130 degrees (and to never set it lower than 120 degrees). Does it save on coal if set to a lower temperature? I'm assuming that if it is set too low the potential for an out-fire is increased, but the lower it is set, the less likelihood of unburned coal going into the ash pan. Is this a correct assumption?

lsayer, I know since you have the instructions for your unit, this isn't any new info. But, for those that may not be familiar w/ the digital ash grate temp controller, I am adding this excerpt to shine some light on AHS's designed process:

THERMO ASH-MONITORING GRATE CONTROL OPERATION
Ash that contains fuel that is not fully combusted will be a higher temperature than ash coming from thoroughly combusted fuel. The Thermo Ash-Monitoring Control automatically monitors the temperature of the ash leaving the coal pot. This provides a feedback mechanism for grate regulation that reduces the need for post install adjustments. Typically, no adjustment other than the factory adjustment is necessary to have the boiler perform at peak power output throughout the burn season (a minor on-site adjustment may be necessary when the boiler is first installed). With the Thermo Ash Monitoring controlled grate, it is possible for the fire to remain lit for days during low usage periods without having to adjust the grate controls by hand, as would be necessary in a timer-based grate control system.
If an ash temperature sensor is used, it should be set at 130° for normal operation. During periods of light demand, reducing the setting to 120° will aid in maintaining the proper level of coal in the coal pot.

I wonder if my earlier out-fire was due to the S.V. setting being 140 degrees from the factory? Is it possible that the boiler dumped its fire due to the control being initially set too high?

Larry

IMHO not likely, its only 10 dg difference, maybe expect a little more unburnt from more ashing.
Did you have a good fire going before your fire went out ?

Your Out-fire...

Since your cold start up was w/o a deep bed of ashes underneath the first hot coals...all bets are off as to the exact reason to the out-fire.

Because of no ashes at cold start-up you would of needed 2-3 hours of continuous demand at maximum out-put...all windows open if you can't stand the heat.

It takes a real good load on that boiler to establish a PROPER bed of HOT coals. Hot coal bed needs to fill completely and evenly both vertically and horizontally in the fire pot...miss that and you'll have extra un-burnt coal and a probable out-fire.

Any of this sound like what happened?

McGiever wrote:Your Out-fire...

Since your cold start up was w/o a deep bed of ashes underneath the first hot coals...all bets are off as to the exact reason to the out-fire.

Because of no ashes at cold start-up you would of needed 2-3 hours of continuous demand at maximum out-put...all windows open if you can't stand the heat.

It takes a real good load on that boiler to establish a PROPER bed of HOT coals. Hot coal bed needs to fill completely and evenly both vertically and horizontally in the fire pot...miss that and you'll have extra un-burnt coal and a probable out-fire.

Any of this sound like what happened?

This plus the 60 degree weather and little demand for heat in the house right after I first fired it up could be it exactly. It's running fine now with temperatures in the mid 40's.

You thought I was crazy when I suggested blasting water through the tankless for an hour or two. It is very important to put a heavy load on the boiler and make sure the entire firepot is burning.

That has been my experience too. I fired my tonight and kept a close eye on it and it took close to 3 hours in order to get a full pot of burning coal. 5 hours later she seems to be holding her own without any intervention from me turning the grate motor on and off while I jogged the burning coal lower and lower while maintaining dem pretty blue flames on top when the ID fan was running.
Feel like I should send a sympathy card to my oil supplier this Christmas.