Axeman Anderson Boilers on a Timer

I'd like to start a discussion about using a keep fire timer on the Axeman. Under moderate heat demand during normal wintertime usage, I've found that the timer isn't really needed. During shoulder months with a stretch of mild days I would keep the Axe lit for domestic hot water but would have frequent out fires, which I attribute to loss of natural chimney draft.

Also, during mild weather there would be a lot of chunk in the ash. I even tried sifting my ash for a few weeks (I know color me nuts lol) to see exactly how much coal was going into the ash tub. I found that the reclaimed coal was half the weight of the ash. For example, out of 40 pounds in the ash I could recover 20 pounds of coal. Which isn't as bad as it sounds.. realistically its 10% waste.

I have interest in running my Axe further into the shoulder months for DHW, so I'm hoping to hear from those that use a timer on their Axe, the details of the timing and how to wire it so that it resets after a combustion call from the aquastat. Anyone knowledgeable about keep fire timers please feel free to comment

I have a timer on mine and I have tried to use it a few times over the years during the shoulder months.

It never worked out for me. It seems like the 2, 3 or even 4 minutes every 45 to 60 minutes isn't enough run time to get the Axeman out of hibernation. If you run the timer more than that you risk some nasty overshoots when things are running normal.

-Don

Thanks Don.. that's excellent information. Perhaps a timer in tandem with the exhaust temperature is in order here.

For example a timer that runs for 5 minutes or reaches 250 degrees would cut out.

Lightning wrote: ↑

Sun. Dec. 05, 2021 12:14 pm

Thanks Don.. that's excellent information. Perhaps a timer in tandem with the exhaust temperature is in order here.

Hummmm,,,,

That's an idea I haven't tried. I have the parts to do it. Maybe we'll give it a try in the Spring. We're beyond the shoulder months now so it's not needed at the moment.

-Don

Right... another concern is resetting the timer after a combustion call from the aquastat. You wouldn't want the timer to run right after a combustion call, so how do you wire that? I think Rob knows how to do that.

I think a timer that recognized a specific temperature in the exhaust stream would be perfect since it would take into account the variable condition of the hibernating fire. In this case, maybe a reset wouldn't even be needed.

Is it true that it takes several hours (or up to days?) for the 130 fire to go out without a timer call? My keystoker is like...2 hours...

I've gone well over two days.

coaledsweat wrote: ↑

Sun. Dec. 05, 2021 4:54 pm

I've gone well over two days.

Maybe you have a good chimney draft that pulls a little combustion air thru the fuel bed when its not running. I've noticed that on mild days when my draft falls to zero I lose the fire in a 3-4 hours. Or maybe it takes a little longer, I've never really timed it..

There's no draft through the fuel bed when an Axeman is at rest. The observation port cover opens and kills it.

coaledsweat wrote: ↑

Sun. Dec. 05, 2021 5:34 pm

There's no draft through the fuel bed when an Axeman is at rest. The observation port cover opens and kills it.

Right... even though the observation port opens, there is still a minute amount of negative pressure inside the burn chamber. Even though thru the fuel bed is a path of more resistance, I'm thinking some air trickles thru it to keep the fire alive.. it must since zero oxygen would mean zero combustion and that would extinguish the fire.

Have any of you guys switched over to solid state timers? I tried one and it drove me nuts because it would lose a few minutes every day...how that makes sense for an electronic device to be so inaccurate. I even called the manufacturer and they told me it was normal...well for $133 bucks that's pretty lousy so I went to my honeywell combo t-stat timer whatchamacallit

Retro_Origin wrote: ↑

Sun. Dec. 05, 2021 6:03 pm

went to my honeywell combo t-stat timer whatchamacallit

Could you post the model?

Lightning wrote: ↑

Sun. Dec. 05, 2021 5:52 pm

Right... even though the observation port opens, there is still a minute amount of negative pressure inside the burn chamber. Even though thru the fuel bed is a path of more resistance, I'm thinking some air trickles thru it to keep the fire alive.. it must since zero oxygen would mean zero combustion and that would extinguish the fire.

Lack of oxygen PLUS coals going cold kills a fire. Insulated coals as in being covered with insulating ash are very viable to reignite because they have retained the heat needed but lack the oxygen that is the missing piece of the fire triangle hence the term hibernation.
I’m sure there is some oxygen seepage still, like iron rusting with oxygen at least.

Retro_Origin wrote: ↑

Sun. Dec. 05, 2021 6:03 pm

Have any of you guys switched over to solid state timers? I tried one and it drove me nuts because it would lose a few minutes every day...how that makes sense for an electronic device to be so inaccurate. I even called the manufacturer and they told me it was normal...well for $133 bucks that's pretty lousy so I went to my honeywell combo t-stat timer whatchamacallit

Yes. I have a Macromatic solid state unit. It is extremely accurate.

Rob R. wrote: ↑

Sun. Dec. 05, 2021 6:40 pm

Yes. I have a Macromatic solid state unit. It is extremely accurate.

Could you link to your post the details of your timer?