Trouble Getting Enough Heat From Coal Boiler

What temperature should I have on the stack? How do I know if it's too high and I'm loosing heat up the chimney?

It is a wood burning design.
Burning coal is going to be a bear.
The V shape compacts the coal ash and that is the issue.
Search thru 'LSFARM' posts about firebox designs.
Swap your wood burning design for a coal burning design and you will love using the coal.

Well, I'm kind of stuck with it for this winter. Maybe I can sell it during the summer and get one with a coal burning design.

Any suggestions on how to operate the best way with a V bottom shape?

What temperature range should my stack be at?

Stack temperature should be 350--400 measured inside the pipe, less if measured on the surface.

It is possible that with forced draft that heat is going up the chimney before getting a chance to be absorbed by the boiler. Try lowering the draft setting, but keep the bed full. Try for a nice glowing bed and not the fierce fire you describe.

The vee type of bed just means it will be harder to clear the ash, but should work.

Richard

I have a induced draft blower on my boiler had the same problem,all the heat was going up the flue pipe. only use draft blower now when I add coal too get fire going good before I slice through to remove ash.

bluegas wrote:I have a induced draft blower on my boiler had the same problem,all the heat was going up the flue pipe. only use draft blower now when I add coal too get fire going good before I slice through to remove ash.

Air is mostly nitrogen so any air in excess of the amount needed for combustion just carries the heat up the chimney. Measuring Co2 in flue gas is just a roundabout way to measure excess air.

Richard

I put a magnetic thermometer on the flue pipe above the damper. It is reading between 250 - 300 degrees. I have the damper closed 90% of the way.

Freddy wrote:I think your heat is going up the chimney. Get proper gauges to see draft & stack temps.

That would be the first place to look. My guess is that thing is around 90-100K.

Hi, The other day I purchased a used and in good condition Jensen 30B. I have a single page spec sheet for it. Nothing on this spec sheet suggests use of coal, to the contrary. the Model 30B info reads: width: 23'', height: 40'', depth: 30'', weight: 625 lbs, 'takes logs up to 28'' '

Then again, it does also read: "This advanced ADD-ON design solid fuel burning boiler ties into your present hot water system and will provide you with a remarkable savings in fuel costs. The Jensen Boiler has an integrated control system that regulates room temperature, system temperature, and operating pressure."

Other info is: "Standard Features"

Secondary Combustion Chamber with Bypass
Firebrick Sides
Heavy Cast Iron Heat Baffles (front and rear)
Heavy Cast Iron Shaker Grate (standard)
Heavy Cast Iron Feed Door featuring Safety Pressure Flap (Fiber Rope Seal)
Removable rear Heat Plate
Heavy Cast Iron Ash Door with Exclusive Shaker Grate Locking Lug (Fiber Rope Seal)
Hot Water Temperature Control
Electrical Relay Control
Thermostat
37 CFM Draft Fan
Draft Fan Barometric Pressure Relief Valve
Temperature and Pressure Gauge
Silver Gray Hammer Tone Custom Painted Shroud Set
Domestic Hot Water Tank (and extra I think)

5 year limited warrant

Jensen, since 1922 A product of Jensen Metal Products, Inc. Racine, Wisconsin, 53403

If anyone has a real manual for the unit I would love to see it. I suspect that there must be some guidance about use for coal versus wood if in fact it is intended for coal as well.

Not too likely, but I've seen.... that if a separate circulating pump is installed on the Jensen and the flow is
against the flow of the other, it would delay heat transfer. Make sure the arrow on the circulating pump(s)
is facing downward, and not in opposition to each other.