Econoburn with storage controls?

Some people use a timer and guess on the length of the burn. some have used the flu temp to shut off the fan not exactly sure how but remember reading a thread on it. Some thing I'd like to do to mine. I'm currently using the timer method.

I have the controller pluged into a timer so when the time is up the fan and pump both shut off. Then I just draw from storage.

goosegunner said:

.... My concern is hot coals and refractory in the boiler with no water moving through it if the main pump stops too soon.

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I don't use an automated shutdown (no storage), but am posting to second your concern. We get a lot of solar gain, and this allows the boiler to be shut down for varying periods of up to 10 hours. For the longer shutdowns, it's important to have the boiler be as hot as possible at shutdown, in order to not drop so low as to prevent an easy restart (the OB is in series, and also don't want that to go too low either). We shutdown when the boiler as hot as possible, but empty of wood - just a very few coals at most. I've watched the temps while doing this, and most of the time the P/T gauge will rise 5-10 degrees from the shutdown temp, before stabilizing. So, you definitely have a valid concern there. If you happen to stop an already (very) hot boiler (and the pump), and also have a big pile of coals going, it's easy to imagine a quick rise and boil over. Maybe the chance of this happening is small, once you get to know how your boiler runs, but I think it would be better to tie an automated shutdown into flue temp, which should be a reasonably fail-safe approach.

goosegunner said:

woodsmaster said:

I have the controller pluged into a timer so when the time is up the fan and pump both shut off. Then I just draw from storage.

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How much do you put on the timer?

My concern is hot coals and refractory in the boiler with no water moving through it if the main pump stops too soon.


gg

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I Just guess use an educated guess estimated by the size of load in the firebox and add an houre or two to that to be safe. An automated control would be the way to go.

Am I understanding correctly (from what I'm reading) that this furnace just keeps on running, even after the fire goes out, until manually turned off? That doesn't seem right to me?

The woodgun is the same except you can order it with a "low temp. shut down" option which shuts the boiler down after the water temp. starts to fall. It runs of an aquastat, there must be a way to do something similar to the econoburn. This option should be standard on all boilers with a combustion fan.

maple1 said:

Am I understanding correctly (from what I'm reading) that this furnace just keeps on running, even after the fire goes out, until manually turned off? That doesn't seem right to me?

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Yes thats the way most of them are. It's up to the installer / operator to set up a control. It would be nice if it was a standard feature.

Somtimes the "FUEL" signal will come on and shut the fan off but for some reason it don't allways work.

That seems very odd to me. Even my current dinosaur unit won't circulate when the water temp drops below a certain point - although come to think of it, when my fire goes out the draft door stays open. With an induced draft fan, it just would seem to be a basic design point that when the fire goes out, the fan stops - that thing would be pumping (now dimishing) heat right up the chimney. So I can sure see why this thread was started.

My dinosaur does the same thing with the fan and pump. I added a surface mount aquastat on the pipe coming out so when the boiler cools off the fan stops blowing at 140*. I also have the same dilemma with charging the tank. My thought was this; if you put an aquastat on the tank with a high differential say 30* you could use that to stop the circ pump and fan on the boiler at maybe 180*. Then add another pump and aquastat on the boiler that only runs from maybe 190* as a high with a low differential (5-10*). Use this pump to move only hot water to the tank, then the aquastat wouldn't let the wood boiler run again till the tank is down to 150*. With a big fire going I can see where you could get everything to hot so you would have to plan your fire according to how hot the storage is and the heat load. This how I was going to do mine when I get around to it but I try to collect the parts I can as I go along to save on the expense of it.

The woodgun is the same except you can order it with a “low temp. shut down†option which shuts the boiler down after the water temp. starts to fall. It runs of an aquastat, there must be a way to do something similar to the econoburn. This option should be standard on all boilers with a combustion fan.

I am new to burning wood in a boiler and am in the process of getting my new Wood Gun hooked up with storage. I did not order a low temp shut down option. Nor was I asked if I wanted one installed. I was wondering how it would turn the fan off when the fire burned out, and found this post while reading the many I have missed over the last three months.

What do the owners of the Wood Guns do about shutting their boiler off if you do not have the low temp. shut down option? How does the low temp shut down work? An aquastat? How does it allow the furnace to turn on in the first place and get started when the temp is low if you are just starting the fire from the beginning or when you have let it go out?

Now is the time for me to have my boiler guys wire something up. If several of you could try to explain a solution and I could relay to my guys, I would appreciate it very much. Keep in mind that I am boiler/mechanical/electrical knowledge and experience deficient. :cheese:

Thanks in advance for your time.

Gasifier said:

The woodgun is the same except you can order it with a “low temp. shut down†option which shuts the boiler down after the water temp. starts to fall. It runs of an aquastat, there must be a way to do something similar to the econoburn. This option should be standard on all boilers with a combustion fan.

I am new to burning wood in a boiler and am in the process of getting my new Wood Gun hooked up with storage. I did not order a low temp shut down option. Nor was I asked if I wanted one installed. I was wondering how it would turn the fan off when the fire burned out, and found this post while reading the many I have missed over the last three months.

What do the owners of the Wood Guns do about shutting their boiler off if you do not have the low temp. shut down option? How does the low temp shut down work? An aquastat? How does it allow the furnace to turn on in the first place and get started when the temp is low if you are just starting the fire from the beginning or when you have let it go out?

Now is the time for me to have my boiler guys wire something up. If several of you could try to explain a solution and I could relay to my guys, I would appreciate it very much. Keep in mind that I am boiler/mechanical/electrical knowledge and experience deficient. :cheese:

Thanks in advance for your time.

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It's been so many years since I scrapped my old Wood Gun that I'm having trouble remembering what I did. I wish I hadn't disposed of my schematics. Never thought they could do someone else some good.
My unit had oil back-up and had a second aquastat that cut in at a particular set-point when the boiler cooled enough and oil would take over, however when the oil brought thr unit back up to temp, the unit thought it had enough wood and automatically switched itself back into wood mode. Then the induction fan would run, taking in outside combustion air, circulating it through the boiler and cooling it down until the temperature was low enough to kick in the oil again. That was expensive
With the help of a friend, we built a box which would lock the unit in "oil" mode until someone got there to light another wood fire. The only thing I can remember about it is that it was very simple and the actual working components were a relay and a time delay relay in addition to a normally open momentary switch (button) and a normally closed momentary switch, a toggle switch and an indicator light to tell me I was in oil mode. I'll sleep on this info for a while and see if any other data flows through my head. If you don't hear from me it's because the data has been permanently lost from my 70 year old brain.
After a year of using the Wood Gun this way, I decided that the oil side on the unit was about the most inefficient way to heat of anything available. I will never get a dual fuel unit for as long as I live.
Wanna feel cheated? Check out this scenario: Load up the boiler in the morning with enough wood to take you through the day. The day turns out to be cloudy instead of sunny, like you expected. Unit either runs out of wood or fails to reignite, oil burner comes on and heats up the unit, all the iron and the water. You get home just in time to hear the oil burner shut down. You just heated everything with oil just in time to build a wood fire. I can't tell you how many times that happened to me.

On my EKO, I only use the controller for the high limit and low limit (low fuel). I use a Techmar 156 to run the circulator for my unpressurized storage which gives me the advantage of the differential thermostat. I don't remember my setting but if the storage is X number of degrees warmer than the boiler the circulator shuts down. I also made use of the second immersion well by installing an aquastat in it and using it to sense an overheat condition. This is wired to a second circulator through a 1500 watt pure sine wave switchable inverter/charger and circulated through a coil in the bottom of my storage tank. It is also useful for moving large amounts of heat away from the boiler to storage instead of having the boiler go to idle during the burn.

This works for me but may not work for everyone. I only burn one 4 or 5 hour fire per day. It is almost always attended and there is never a fire when anyone is sleeping.