Ahss130 Thermo Ash Control

I just installed an AHS s130 boiler in December, hooked it to a heat exchanger in my oil hot air furnace and also have a plate heat exchanger for domestic hot water. Love having unlimited hot water. As a mater of fact we used last week to wash out our maple syrup barrels. It made 150 degree water for 7 hours straight running 2.5 gpm of hot water through the barrel wand. I love this boiler!!. My question about the thermo ash control is how low can I set the temp? I read somewhere in one of the threads that somebody had it set down to 75 degrees. The book says to run it at 130 degrees during normal use and 120 degrees during low demand use. It seems to me the cooler you let the ash get, the more efficient the unit will run. On the other hand if the ash temp. gets too cool, I am assuming that you run the risk of letting the fire go out. Any thoughts on how low I can go?

The way I think about it you want it low enough that you have minimal or no unburned coal in the ash. I find I reach that with a setting in the low 120s so I haven't tried going lower. Having a fire go out can be a big mess and I don't want that.

The axeman and the ash are basically the same,I would have to say it will never ash at 75( my basement is 72 degrees)your fire will go out. I run my axeman anywhere between 125-140. It would seem that the temperature set lower would be more efficient, not that way to me, if it is set too low, it will not have as much draft threw the fire, allowing more unburned coals.

The AHS thermoash control is nothing more than an modern day improvement to the AA mechanical thermostat. Both are switch on switch off controls. What's really needed is a PID type control on the ashing grate thermocouple. PID = proportional–integral–derivative controller. With the proper control algorithm such a system could insure system would optimality ash because it could measure the rate of change of ash temperature. This would assure the fire would not go out and/or only operate the grate motor when needed.

The unanswered question is will it reduce coal consumption. That will not be known until someone actually tries it.

I think the Thermo Ash Monitor picks up heat from the underside of
the boiler.If you run your boiler HOT you have to run the Asher a little
higher that if you run the boiler cooler.Once the unit runs for awhile the
air moving through the bottom gets everything equal and the sensor is
better able to see the temp of the ash.That sensor is the only thing that
lets in more coal other than the fire shrinking down the burning coal.

Right now I wouldn't consider my demand to be light. I am heating a 2,000 square foot house (well insulated ) plus DHW with the current temps of high 20 and lows below 0 the last couple of days. I have the ash control set at 120. What problems do you forsee with dropping it lower, to say 110? then maybe 100. What would be symptoms to look for before I have a problem?

I think at that low temp it will never ash and bring in
new coal.That could cause the fire to burn back into you
overhead hopper on the AHS brand boiler.You have to let
the unit ash or it will go out from lack of fuel.My AA would
never ash at 110 and go out.

gizmo wrote:I think at that low temp it will never ash and bring in
new coal.That could cause the fire to burn back into you
overhead hopper on the AHS brand boiler.You have to let
the unit ash or it will go out from lack of fuel.My AA would
never ash at 110 and go out.

I would agree, I've done it a few times where I turned the temp down and the fire will go out. But I've never seen it burn up into the transfer head on the axeman. I would say to only turn the temp. a couple degrees a day and see what happens, small steps over great leaps.