Combustion problem never fixed Okofen

[Pilpoill]

Without wanting to get too involved, I think that the problem of soot on the chimney is certainly debatable, not necessarily optimal layout, poor adjustment of the boiler, quality of the pellets, ....
But the fallout of soot on top of the boiler, I don't understand! It can only be an installation problem in my humble opinion. A "vacuum" boiler is, by definition, airtight.

Several points of view is what will make progress

[Christophe]

Without wanting to get too involved, I think that the problem of soot on the chimney is certainly debatable, not necessarily optimal layout, poor adjustment of the boiler, quality of the pellets, ....
But the fallout of soot on top of the boiler, I don't understand! It can only be an installation problem in my humble opinion. A "vacuum" boiler is, by definition, airtight.

1 +!

A classic chimney should normally exceed the ridge (there are standards) and be in the prevailing wind and not downwind, but it is less sensitive with the forced draft flue...I think there is a problem elsewhere ...

Because this soot falling on the boiler is WTF!

Where do they come from? Are the tiles visible from the inside?

[Christophe]

I'm not a roofer but I think there is a problem with the 2 surrounded tiles... which should be UNDER the zinc...

Could the soot also enter through the arrow (see interior finish?)?

19.12.22_Vertical suction cup roof.jpeg (445.57 KiB) Consulted 1120 times

[izentrop]

Well done but I guess the room is isolated? and it appears to be tiles added to hold the lead flashing.

There was someone recently who had this kind of problem, which was due to a torn air inlet duct fitting. He was a veteran of forum, I don't remember the subject?

[Philippe Schutt]

"Volcano" burners have 3 operating states:
1- off
2- combustion
3- standby
If the first 2 states pose no problem, the 3rd is debatable.
Indeed, in this state, the boiler cuts the arrival of pellets and the mechanical supply of air, so as to maintain a block of embers in the burner. The combustion is then horrible, polluting and clogs the duct, in particular the anti-bird grilles. This block of embers can last a good half hour, depending on the natural draft of the chimney.
The advantage (and justification) of this system is a very rapid restart of the boiler, allowing the buffer tank to be dispensed with. Hence a saving of almost €1000 on the installation, or a more stable regulation of the T° in the house.

It is very important not to oversize the boiler, to limit these phases. However, installers do this systematically, especially those who are used to oil or gas heaters.

To limit breakage, I suggest programming periods of complete shutdown and limiting the maximum power.

[Pilpoill]

"Volcano" burners have 3 operating states:
1- off
2- combustion
3- standby
If the first 2 states pose no problem, the 3rd is debatable.
Indeed, in this state, the boiler cuts the arrival of pellets and the mechanical supply of air, so as to maintain a block of embers in the burner. The combustion is then horrible, polluting and clogs the duct, in particular the anti-bird grilles. This block of embers can last a good half hour, depending on the natural draft of the chimney.
The advantage (and justification) of this system is a very rapid restart of the boiler, allowing the buffer tank to be dispensed with. Hence a saving of almost €1000 on the installation, or a more stable regulation of the T° in the house.

It is very important not to oversize the boiler, to limit these phases. However, installers do this systematically, especially those who are used to oil or gas heaters.

To limit breakage, I suggest programming periods of complete shutdown and limiting the maximum power.

What you call the "eve" is not exactly what you describe at Okofen

Once the end of combustion has been ordered, there is a post-ventilation time for the fireplace that can go on a Compact up to 600 or even 1800 seconds (depending on power 10/18kW or 22/32kW) to allow the end of combustion of the pellets present on the combustion plate.
The real time is calculated according to a temperature delta set by Okofen.

[Philippe Schutt]

If it vents, all the pellets should be burned and Okofen does not use this 3rd mode. So the buffer tank is necessary.
And the problem comes from elsewhere...
Can we know the operating times at the different powers?

[Philippe Schutt]

Ah, I just looked at the compact and on this boiler they have abandoned the volcano burner, the pellets come from the side and it is not possible to create a large block of embers. So I said something stupid, and I apologize for that.

[izentrop]

I found the topic renewable-energy/black-traces-under-pellet-boiler-exhaust-duct-t17415-20.html#p524165

It was the same kind of chimney outlet, but horizontal.



On the other hand, the smoke outlet is at the end. The air inlet is through the side openings...
Could the heating engineer have reversed air and smoke Still not



The length of the roof outlet (yours) also seems a bit short to me.

[Pilpoill]

With the last comments of this subject, I wonder if the problem is not quite simply due to the assembly of this stainless steel outlet.
On mine, it seems to me that the large circular part is located on the top so that the fresh air can be taken in UNDER the fumes.
So I ask the question again, what did the result of the gas analysis test give?

I'll take a picture when I next visit...