LL Boiler - Questions about dual fuel ect.

The auto changeover option is being worked on the 220K btuh unit and will add about $700 including the oil gun and associated controls. As has been stated here keep it simple if at all possible, running your old boiler as back up is always a good idea if room is available and it is in good shape. Having said that you have increased failure probability if the unit is old and on it's last legs.

whistlenut wrote:Remember guys, you might have a boiler online anyway, or if it is a brand new installation, why not consider the base LL boiler and have a separate oil or gas boiler?! You could buy an oil or gas boiler new or used for short money and not even have to think about the changeover of fuel types in an emergency. I know everyone wants this to all be in a sweet gift wrapped little package, but that has a price, one that would be far greater than a separate boiler. In the highly unlikely event that a coal unit would fail, having a plan 'B' is admirable, but understand that I have 3 260's running for over 35 years without any oil or gas backup (another coal boiler sits as a reserve) and people live in apts that require heat and hot water 24/7/365.

whistlenut, I know this topic has been beaten to death over the years. The biggest concern/issue is the lack of efficiency in one of the fuels in a dual fuel. Usually it's the oil. Since the oil is the backup or just for summer hot water, I would argue that the lack of efficiency in oil is not a huge concern. Coal would be the primary heat source & the unit was designed for coal.

I agree that having a backup boiler is nice (we are all engineers at heart and we love multiple redundancies), but as you stated the reality is that the probability of having to use the backup boiler oil boiler when you have a duel fuel boiler is highly unlikely.

What intrigued me about this design was the fact that this was an Axeman boiler originally designed for oil. And if it has Pete Axeman's & Matt's blessing on coal, I would think that it is pretty efficient on both the coal & oil side.

whistlenut wrote:One other thought, in wiring your controls, we ALWAYS bypass the circulator functions of a 8124 or whatever, and wire the pumps or zone valves to open or start on demand through a Taco controller, regardless or the temp of the boiler. If you lose fire for any reason, you still have circulation, and moving water will not freeze. This is not new, we have done it this way for 40 years. I know it gets just as cold where you live, and copper snaps in a heartbeat if it freezes there also.....just saves the 'emergency nature' of an outfire when it's 10 degrees out.

I never heard that mentioned before, but it is a great idea!!! I'm going to do that in my house & in my tenants apartments. I spent one Sat with my mechanical guy thawing out their entire apartment this winter, fixing breaks b/c they ran out of oil.

whistlenut wrote:There are other ways to make your dollar go further, and yes, Dave and Matt can engineer an auto changeover system for fuels, but it is not necessary IMO. It could double the price, and I see no reason for adding the complexity. KISS philosophy works every time. This is not rocket scienc

I agree that double the price would not be worth it. I would stick to the manual switchover on oil. But if they could do it for an additional $700. That's worth every penny in my opinion.

Matthaus wrote:The auto changeover option is being worked on the 220K btuh unit and will add about $700 including the oil gun and associated controls. As has been stated here keep it simple if at all possible, running your old boiler as back up is always a good idea if room is available and it is in good shape. Having said that you have increased failure probability if the unit is old and on it's last legs.

No plans on the 110K?

Space is an issue for me. I'm sure I could get creative & figure out the spacing issues & power vent the oil boiler, BUT a dual fuel auto switch over coal boiler would free up some much needed space to put a coal stove back in the basement!

And that's what it's all about right? Heating with coal!

For my education, and out of curiosity, I have been researching coal boilers and coal furnaces that have the capability to automatically swith over to burning oil if the wood or coal fire were to fail for any reason. The key feature needed is a seperate fire box and dual thermostats.

The only company currently selling a unit(s) that has automatic change over seems to be Harman.

http://www.harmanstoves.com/products/de ... =FURSF2600

http://www.noutilitybills.com/Furnaces/ ... 00-SS.html

"Although it’s one of the most versatile units on the market today, the Harman SF-2600-SS Furnace uses no more floor space than our other furnaces. Plus, it’s the only multi-fuel furnace with and 85 percent efficient oil burner system. The oil burner fires into a separate combustion chamber, so you can be sure the oil nozzle will never clog from the soot from wood or coal fires.

Two separate thermostats – one for wood or coal and one for oil – let you set your furnace to burn oil as a backup in case your fire burns out. Or you can set it to burn oil as the primary fuel. It’s that easy."

My $.02 on common unit with auto change over. - Don't bother if you want to burn wood. I have an auto change over HS tarm and my Dad had an combo AHS wood gun. If you have a problem with the boiler or the chimney, you are SOL with no heat. I won't detail the problems we had but trust me, we both installed backup boilers totally separate from the wood system. Now I realize and admit coal will have fewer problems than wood.

As far as coal, the problem I see, is again, if you have a problem with the boiler(controls, pump, leak, etc) = no heat. I forsee an ash buildup problem on the oil gun in a unit with a common chimney. The one time it is needed, it won't fire due to fouling as it will have been forgotten about. Even with a separate combustion chamber, if it is common vented, fly ash will get in it. Also, some areas won't permit oil and coal vented in to the same chimney and the inspectors view a combo unit as a violation of this prohibition.

Why would you need auto change over on a stoker? Forget to fill it or take out the ash? I suppose an outfire might be possible but highly unlikely in colder weather.

If you want back up heat to be truly backup, install a separate boiler in parallel and use staging controls. More dollars, more space but more reliable.

Personally, I plan to install a propane boiler as backup and get rid of the oil. High efficiency propane units are just as cheap or cheaper than an oil unit and can usually be vented through pvc. Propane doesn't go bad sitting around and is convient to use for stove, summer domestic hot water, and clothes dryer. Maybe a dollar or two a million btu's more, but with coal as primary, little back up fuel is actually used.

Along the lines of this conversation..... I bought a house that had a dual set up. An oil boiler and oil on demand DHW and a wood boiler with a large water holding tank set up next to it. I sold the wood boiler when we moved in (don't like burning wood). For the last 3 years I have been using an alaska stoker insert in an upstairs fireplace. It handles about 70% of our heating needs but we still spend $1500 a season on oil for water and as a back up. This year we want to get rid of the insert and put in the leisure line 110 boiler. My question: can the new boiler go where the old wood boiler was and can we keep the existing oil as a back up. The oil now has two zones but the wood boiler did not. Each was run on a separate thermostat (2 for the oil zones and 1 for the wood boiler). I would like to zone the new coal boiler as well. The wood and oil both pumped into the baseboard of the house and vented out the same chimney. It seems it would be easiest to just put the coal boiler in place of the old wood boiler and can the coal utilize the water storage tank that is still there. Really I want to be able to go on vacation and leave the coal burning and have the old oil boiler kick on when the coal burns out. Also, should I fire up the oil boiler from time to time to keep it running smoothly?

thanks

From a manufacturer's standpoint, the more recognized and accepted their product becomes, the more they profit.

If Leisure Line, EMF, AHS, Keystoker and others wish to make their products "mainstream" to the average consumer, they need to do the following in my opinion, as a minimum.

A). Offer the Coal-Trol Digital Ignitor system once the issues with the element failure rate have been rectified.

B). Design a coal furnace with automatic change-over from coal to oil or natural gas.

Which to us, the heterodox consumer, we may seem as a cult to others because we readily accept such an unorthodox product as one that's fired by coal which is no longer an accepted form of fuel as it once was.

You should be able to put the LL 110 where the wood boiler was located . I would by pass the stoareg tank as it will most likely be uneccesary and will make th unit less efficient however. I would place the the LL unit in series with the oil unit and circulatre between the 2 boiler 24/7 and set the aquastat of the oil boiler at a lower point than that of the LL boiler so if you have an out fire or if it can't keep up the oil will come on to supplemenmt the coal. I have never had a outfire other than a lengthy power outage like this week.

Idomeneus wrote:Really I want to be able to go on vacation and leave the coal burning and have the old oil boiler kick on when the coal burns out.

Shut the coal unit down before you leave and fire up the oil boiler. Unless you go on vacation once per month, the savings by doing what you suggested is small compared to the risk or something not going correctly.