Info on combination wood,coal and oil boilers

[BoilerMan]

I may be wrong, but I do not think there are any made that are true gasification wood burners...........accept the woodgun, and lets not get into that as to not confuse a new member.

TS

I knew this would happen....... With all the banter, why is the WG guys always all chime in? I will not endorse that what I burn in is the best just because I have it.

Personally I have operated and installed several solid-fuelled boilers and have had the privilege to see them in operation many years later and assess the install and judge the long term usage of those units. This helps to form an educated opinion of those units and those alone. As well as hone my install skills and materials used, as with any trade, learn from your and other's mistakes.

A combo unit is a mistake unless you have no other choice, one flue........which should not even be a real issue, but code says it is.

TS

 

[avc8130]

I knew this would happen....... With all the banter, why is the WG guys always all chime in? I will not endorse that what I burn in is the best just because I have it.

A combo unit is a mistake unless you have no other choice, one flue........which should not even be a real issue, but code says it is.

TS

The WG guys are "chiming in" because the OP asked about COMBO units. There really aren't many offered, and the WG happens to be one of those that is.

I still fail to see how the combo unit is a mistake. Generally the units are designed to burn wood...with the ability to burn something else as "backup". Who cares if the 2nd fuel is "inefficient"...it's a BACKUP. The whole point is you won't use it.

ac

 

[BoilerMan]

I'm with Maple1, electric backup..... well personally, and you may have read into my posts that I do not have a problem with two units on a shared flue. There are hundreds if not thousands of wood stove/boilers on the same flue as and oil/gas boiler/furnace in so many homes around this county. I'm not one of them, but if I had an older home with one flue and direct venting were not an option I'd connect a gassifier or epa wood stove to the same flue as an oil/gas boiler and not have any issues other than some insurance person. And I'd shop around for insurance if that were the case.

avc: I say mistake because of oil burner nozzle fouling, and the overall inefficiency of the oil side due to fly ash from wood/coal. I've worked on an EFM coal stoaker/oil boiler several times (great unit BTW! ) the oil only works if a shutter is opened and a mercury switch locks out the stoaker and enables the oil burner. Two separate units (or a combo unit the has two separate combustion chaimbers) is all that I would consider. A unit with two separate chaimbers (like what you considered avc) still has all that heated steel to draft heat up the chimney 24/7. Have you connected your oil burner yet to see how it operates long term? Why do you think that plug is there for it?

TS

 

[Fred61]

Who cares if the 2nd fuel is "inefficient"...it's a BACKUP.

Mine was a little worse than "inefficient". It was an oil HOG.

 

[avc8130]

Mine was a little worse than "inefficient". It was an oil HOG.

Did you run it with the fan active or disabled?

 

[avc8130]

I'm with Maple1, electric backup..... well personally, and you may have read into my posts that I do not have a problem with two units on a shared flue. There are hundreds if not thousands of wood stove/boilers on the same flue as and oil/gas boiler/furnace in so many homes around this county. I'm not one of them, but if I had an older home with one flue and direct venting were not an option I'd connect a gassifier or epa wood stove to the same flue as an oil/gas boiler and not have any issues other than some insurance person. And I'd shop around for insurance if that were the case.

TS

That would be "fine". BUT God forbid (is this expression allowed on this forum?) there was a fire...

Another option would be to "swap" flue connectors. It really depends how badly one needs the ability to switch to the "backup" automatically. It wouldn't be tough with the appliances next to each other and the flue connectors pre made to pop one out and the other in.

ac

 

[Fred61]

Did you run it with the fan active or disabled?

I was sort of on my own. Didn't have this site to share ideas. It took me about 4 years to think of disconnecting the draft fan even though I knew (suspected) it was my problem. I also had to build a control box to lock it into oil mode once it automatically switched over or it would switch back into wood mode when the boiler temp was brought back up. If the boiler was out of wood or failed to rekindle it would continue to keep cycling from wood to oil until I got home and switched it off. It didn't take long to burn a tank of oil in that scenario.

It was still an oil hog after the fan was disconnected. I eventually disconnected the oil burner from my home grown control box and used it as a lock to shut down and lock the combustion fan (if no re-light)until I was able to manually reset it.

 

[Fred61]

It really depends how badly one needs the ability to switch to the "backup" automatically

If you have a good amount of storage, switching to back-up will not be so much of an emergency.

 

[avc8130]

I was sort of on my own. Didn't have this site to share ideas. It took me about 4 years to think of disconnecting the draft fan even though I knew (suspected) it was my problem. I also had to build a control box to lock it into oil mode once it automatically switched over or it would switch back into wood mode when the boiler temp was brought back up. If the boiler was out of wood or failed to rekindle it would continue to keep cycling from wood to oil until I got home and switched it off. It didn't take long to burn a tank of oil in that scenario.

It was still an oil hog after the fan was disconnected. I eventually disconnected the oil burner from my home grown control box and used it as a lock to shut down and lock the combustion fan (if no re-light)until I was able to manually reset it.

Oh have things have changed (and stayed the same). WGs now have PLC controls. Once the boiler switches to oil, it locks into oil mode until manually reset.

I have what's called a "manual" oil backup. I have to turn off "wood" and turn on "oil" to run mine on oil. I didn't WANT auto backup as my whole intent was to burn WOOD. I want to choose when to burn what fuel. So far I haven't chose oil since...in fact I don't even have my gun installed.

So yeah, I can't speak from personal experience on the oil burning front with my WG. I just read about others turning off the draft fan to reduce flue temps and get a better oil burn.

The recommended nozzles for the WG are crazy. 1.1 gph with 150psi pump pressure is insane for my E180. That is WG trying to get the FULL 180k btu rating out of it. When I finally get around to installing oil, I will probably start with a .85 nozzle. I'll play with it until the oil burner doesn't short cycle. That is HORRIBLE for efficiency, just like it is with wood.

I think the thing to remember with burning oil in a WG is that it was designed to burn wood. Burning oil is a side-effect to keep the "backup" around.

I certainly would not suggest to anyone that they buy a WG or ANY combo unit if they plan to use the oil for anything more than a "BACKUP".

ac

 

[Fred61]

Yea, I had to build my own control. Manual oil backup is what I essentially ended up with only I had to physically connect a wire since I never added a switch. Actually I've operated a couple combo hot air smoke makers in the past and they were very inefficient also so I personally have come to the conclusion that most combos are less than ideal when it comes to efficiency.

 

[maple1]

After being without oil all together for just over a year now (I finally just got my oil tank out of the basement this past weekend though), I would honestly recommend that oil be about last on the list for backup heat. Electric heat can be expensive to operate, sure - as primary heat. But there are so many electric options (boiler, baseboard, radiant plug-ins, mini-splits), that oil pales in comparison. Especially considering that last one can give you A/C in the summer, and is very efficient. Then you get into the gas powered options. All of those make for a cleaner install than oil - no chimney, potential oil spill hazards, ongoing burner maintenance, or worries about fuel gelling or going bad. I would even recommend yanking an existing oil unit, that might be working OK now, in favour of something else, especially if your oil tank has many years at all on it.

My experience has really made me realize how bad our oil addiction is - I'm glad I broke mine.

 

[BoilerMan]

Oil at one time was the cheapest fuel, aside from coal and wood. Most coal plants (boilers) were converted to oil for their relative low maintanice and automation. Now, I walk into schools and other large institutions build in the golden era (1950s) that have old coal bins that are now filled with mechanicals and other boiler room appendages. The coal replaced with 15,000 gal buried oil tanks converted in the 60s and the old AxmanAndersens long scrapped.

Looking back they should have stayed the course with coal. They are now installing dual fuelled burners on those 60s boilers (W-M) and going with buried propane tanks in conjunction with the 15,000 gal oil, which was once bunker-C. I'm there wiring in the new burners. We tried to talk them into biomass chip boilers to supplement the oil, but the expense and logistics were simply not there......especially with steam from the 50s in the building.

TS

 

[hobbyheater]

Looking back they should have stayed the course with coal. They are now installing dual fuelled burners on those 60s boilers (W-M) and going with buried propane tanks in conjunction with the 15,000 gal oil, which was once bunker-C. I'm there wiring in the new burners. We tried to talk them into biomass chip boilers to supplement the oil, but the expense and logistics were simply not there......especially with steam from the 50s in the building.
TS

Interesting stuff !
HH

 

[Fred61]

Oil at one time was the cheapest fuel, aside from coal and wood

I can still remember my mother wiping away tears when she received a notice from the oil company back in the fifties that the price of fuel oil was increasing to eighteen cents a gallon and the discussion with my father on how they were going to pay for it.

 

[Gasifier]

I can vividly remember getting $600 + oil bills when filling the tank and heating my home with it. I have spent about $300 dollars on oil in the last two years now. $150 of it is still in the tank.

 

[velvetfoot]

Generally, is propane getting cheaper? Around here it's been more than oil, and not sure if that's changing. Change to propane=a freed-up flue, standby generator possibility.

 

[Gasifier]

That looked like hell. Still wish I had natural gas down my road.

Here is a good chart. http://chimneysweeponline.com/hofuels.htm

 

[BoilerMan]

Propane is much cheaper now that people are buying it in quantity (replacing oil with it). If you only buy a few hundred gallons/year it's much expensive. So for us cordwood burners, having LP as backup is expensive BTUs but will not go bad in the tank in five years.

TS