Friday, July 14, 2006

Dor, Opop, Baxi, Boink, Eco, Gerkross, Scotte, Viadrus

Viadrus - Opop - Dor - Atmos - Baxi - Roca - Scotte - Boink - Eco - Gerkross

I have explained the difference between a boiler and a burner unit in previous posts. The boiler
being essentially a kettle in which water is heated and then pumped to your radiators etc. The
burners is a fire-making device that uses gas, oil, or wood pellets, as the case may be, to generate a flame and thus heat the water in the boiler.

Integrated pellet Heating Units

I have also explained that there are "Integrated" boiler/burner/hopper units available, in other
words, specially purpose designed wood pellet central heating units with all the bits in one box
as it were. These tend to be much more expensive that the separates. The Kunzel is one
example of an integrated unit. The Gerkorss really is not, as it is essentially several unique bits
bolted together. You could bolt a Boink Burner to a Gerkross and get it to work - how well I
wouldn't know - but it would work!!

Boiler Burner Separates

In the separates, the boiler is usually an existing logwood burning boilers with a few
modifications so the "burner" can be bolted to the side or to the front. There are a number of
different makes around, Opop and Dor, Viadrus, Atmos. Baxi/Roca being five fairly popular

The Marriage of Boiler and Burner

Any one of the many boiler units can be married with most any one of a number of pellet burner units, with a few considerations for size, output, flame size, efficiency and the like. There are lots
of burner units on the market. They can be divided into a number of categories. You could
therefore have for instance a Viadrus boiler with a Scotte burner, or a Opop Boiler with a Boink
Burner, or even a Gerkross Boiler with a Scotte Burner etc. etc. Many variations are possible.
Some marriages will work a bit better than others naturally.

Feed Type.

1. Top fed. Where the pellets are dropped in from the top onto the burning grate.
2. Lateral Fed. Where the pellets are pushed in from the side.
3. Bottom fed, Where the pellets are pushed up from under the flame.


1. No modulation. There is only one rate of heat and when the boiler has enough it shuts down,
and re-starts again when the heat is needed - like an oil burner which stops and starts all the
time. Problem with a wood pellet burner is that each re-start takes maybe 20 minutes to
complete; it also puts a strain on the mechanism, especially the igniter element.

2. Two or Three Step Modulation. This is where the burner can cut the heat down to 50% when
no so much heat is needed, or turn off as necessary. The Gerkross Boiler/Burner uses this

3. 10 - 50 or 100 Step Modulation. On these burners the flame is controlled to the needs in
several small increments of need - like in a gas boiler.

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