Medium Biomass Boiler

[cornish wood burner]

With a decent boiler there should be no smoke as long as it's set up correctly.

Furnace temp needs to be high for complete combustion. Water return temperature needs to be controlled otherwise cold spots, and condensation will occur. A buffer tank is desirable but not essential with the right plumbing. You need a thermostatically controlled 3 port valve on your return. I keep my boiler returns above 65 deg C but. You could experiment with it.

[cornish wood burner]

With a decent boiler there should be no smoke as long as it's set up correctly.

Furnace temp needs to be high for complete combustion. Water return temperature needs to be controlled otherwise cold spots, and condensation will occur. A buffer tank is desirable but not essential with the right plumbing. You need a thermostatically controlled 3 port valve on your return. I keep my boiler returns above 65 deg C but. You could experiment with it.

With a simple heat exchanger you would be far better off with a tank unless your load will absorb maximum boiler output which it sounds like it won't.

[Celtictimber]

Its a GF295 boiler

40ft shipping container with 2.64KW fans

 

 

I had the same problem with ours in the start.

They don't like recycled wood much and they don't like to be too full. I've had mine just over a year now and find it burns best with small amounts and often also smaller size fuel. We burn oak beam off cuts. Don't fill it higher than the secondary air vents and keep the blower speed on max.

I find it smokes when first lighting so I light the fire right at the back and leave the door open until it's a good roaring fire. It always smokes a bit when the blower shuts off but no more than a log burner would.

[Duffryn]

I had the same problem with ours in the start.

They don't like recycled wood much and they don't like to be too full. I've had mine just over a year now and find it burns best with small amounts and often also smaller size fuel. We burn oak beam off cuts. Don't fill it higher than the secondary air vents and keep the blower speed on max.

I find it smokes when first lighting so I light the fire right at the back and leave the door open until it's a good roaring fire. It always smokes a bit when the blower shuts off but no more than a log burner would.

 

Agreed the key to getting the most out of a GF boiler is keeping the fuel below the secondary air vents. This rather defeats having such a large fuel chamber and means that you have to refuel on a regular basis but its the only way to reduce the smoke ( i.e by allowing the secondary air to do its job)

[difflock]

Our 40 kW Solarbayer, and now about 10 years old burns/burned ABSOLUTLY cleanly, despite being stuffed to absolute maximum with split conifer, after a little smoke during start up.

Contrary to the instructions in the manual provided, I found it best to get a good roaring fire established with cardboard boxs and kindling consisting of the finer & splintery bits from the splitter, then "load her up" to complete firebox capacity.

Drawing through 12m of twinwall flue, but ZERO visible smoke or even any perceptible haze.

Oh and a buffer tank fed through a Laddomat.

marcus

[cornish wood burner]

Agreed the key to getting the most out of a GF boiler is keeping the fuel below the secondary air vents. This rather defeats having such a large fuel chamber and means that you have to refuel on a regular basis but its the only way to reduce the smoke ( i.e by allowing the secondary air to do its job)

What temperature does your return water go back at. Could it be too cold and pulling the combustion chamber temperature down?

[cornish wood burner]

Our 40 kW Solarbayer, and now about 10 years old burns/burned ABSOLUTLY cleanly, despite being stuffed to absolute maximum with split conifer, after a little smoke during start up.

Contrary to the instructions in the manual provided, I found it best to get a good roaring fire established with cardboard boxs and kindling consisting of the finer & splintery bits from the splitter, then "load her up" to complete firebox capacity.

Drawing through 12m of twinwall flue, but ZERO visible smoke or even any perceptible haze.

Oh and a buffer tank fed through a Laddomat.

marcus

That sounds absolutely right. A good hot burn brought about by a good flue, a laddomatt to keep the return temp up and a buffer tank to keep it running hard. Perfect.

[MonsterMonster]

40kw Eco Angus Orligno 200 connected to 3000l Akvaterm with a Laddomat loading valve. Initially we had a clean burn with just a heat haze. At startup it's puffing billy. However clogged heat exchanger tubes caused reduced combustion leading to smoke and neighbour concerns. Also added low profile rain cap may have reduced draw. At installation the boilers primary and secondary air feeds should be balanced to match the draw of the flue which most installers don't do. Balancing is tricky job requiring expensive kit to do it properly. Boiler is cleaned and new rain cap installed, dry wood but we still get some smoke so aim to burn over night and run off store.

 

Sent from my Alba 10" using Tapatalk

[cornish wood burner]

40kw Eco Angus Orligno 200 connected to 3000l Akvaterm with a Laddomat loading valve. Initially we had a clean burn with just a heat haze. At startup it's puffing billy. However clogged heat exchanger tubes caused reduced combustion leading to smoke and neighbour concerns. Also added low profile rain cap may have reduced draw. At installation the boilers primary and secondary air feeds should be balanced to match the draw of the flue which most installers don't do. Balancing is tricky job requiring expensive kit to do it properly. Boiler is cleaned and new rain cap installed, dry wood but we still get some smoke so aim to burn over night and run off store.

 

Sent from my Alba 10" using Tapatalk

Different woods require slightly different settings. My boilers adjust most of the secondary settings automatically to hold the excess O2 within tight limits. It might be your primary air is driving off too much volatile gas for the secondary to burn. I would try increasing the secondary relative to the primary as a first step. Mark present setting before you adjust so you can go back if necessary.

[MonsterMonster]

Different woods require slightly different settings. My boilers adjust most of the secondary settings automatically to hold the excess O2 within tight limits. It might be your primary air is driving off too much volatile gas for the secondary to burn. I would try increasing the secondary relative to the primary as a first step. Mark present setting before you adjust so you can go back if necessary.

The problem is that the intake is a pig to get to: behind screwed in insulated panel upon which the fan is mounted, a lot of dicking about.

 

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