Ancient boiler finally gave up

Greenthumb

I have a 1920's greenhouse on my property that is only used in the early spring to start flowers and veggies for the garden. The boiler finally gave up this spring with a large crack in the rear section. It is a wood/coal boiler, gravity hot water system that is drained every fall to prevent freezing. The pipes are 3inch under the benches and 2 1/2 inch going from the boiler to these. The system probably holds about 75 gallons of water. The system worked very well. The temperature in the house is the same front to back. Because the piping is under the benches, the plants grow quickly from being heated from below. I would load up the boiler in the evening when I got home from work to bring up the heat, add a couple of logs before going to bed, and if it was going to be a cloudy day add a couple of logs in the morning before going to work.

What is the best replacement for this situation?

Since this is not a commercial house and I don't earn my living from it, I want to keep the cost down. My thoughts keep coming back to whatever I replace it with, will it fail from corrosion from being drained every winter and being an open system? If I close the system and don't drain it, antifreeze will set me back $$ plus the possiblilty of a leak costing hundreds more in antifreeze. I only burn about a cord of wood a season. Oil or gas would work equally as well. The heat loss calculation comes up to 50k btu/hr.

Did I mention that the boiler is located in a pit below the greenhouse? It is going to be difficult to install something different unless it is in sections.

Any ideas?

moneypitfeeder

can you post manufacturer?

I'm betting this a a serious longshot, but maybe a salvage yard would have a section if it were a common boiler. Maybe one of the pros will weigh in as to if a section could be removed and recast. Some small iron shops are willing to do a custom casting, and while not cheap, would probably be less than a whole new boiler. Good luck!

lchmb

room

Do you have room or is it allowed to put an outdoor wood boiler on your property? Then you could not only heat your greenhouse but your main house if you so choose.

Greenthumb

Outdoor wood boiler.....

Honestly, I don't want to feed the outdoor boiler all season. The greenhouse boiler is enough to remind me how much work it is burning wood. I'm happy with Mr. Buderus heating my home.

Greenthumb

How long would you expect it to last?

If I replaced the old boiler with a "new" used wood boiler, how long do you think it will go? Open system. I would have to add a circulator based on the "new" design.

Brad Barbeau

Gasifier

What about a gasifier with storage? If you go to hearth.com there will be lots of information in the "Boiler Room" section. Installing storage would make it possible to load less frequently and be more efficient too!

Charlie from wmass

What sort of gas do you have?

I will look to see how small of a boiler is available. Gas atmospheric would be least expensive for initial cost. It will be least efficient but if you are not using that much fuel is should not be an issue. draining out the boiler should not cause too much more corrosion. Just make sure soon as you fill it to heat it up to drive out the dissolved gases.

Greenthumb

Propane

Charlie- Propane is our only gas option.

Charlie from wmass

Propane may cost a bit more than natural but

I think if I were to have a part time boiler I would go for it. They require service but less involved than an oil boiler. Also less issues with frozen fuel if it is not stored in the building. I have no issues with oil My father heats his home quite happily with oil. I just think the propane would be good for this case.

Charlie from wmass

Also you could close your system with minimal

changing of the system. Gravity still works with a closed system. It just corrodes less.

VictoriaEnergy

Get a used one

Sounds to me like all you really need is a decent used unit. Lots of old equipment is being changed out for higher efficiency replacements that is still in solid shape.  Maybe post some pics of your system and what corner of the world you are located.  Installation of a similar unit would make the job less costly.  Someone might be interested in taking it as a off season job.

VictoriaEnergy

Get a used one

Sounds to me like all you really need is a decent used unit. Lots of old equipment is being changed out for higher efficiency replacements that is still in solid shape.  Maybe post some pics of your system and what corner of the world you are located.  Installation of a similar unit would make the job less costly.  Someone might be interested in taking it as a off season job.