Bonus Plus Instructions Tarm Biomass 1-800-782-9927 Version 11/14 Page 11
2.1.5 Boiler Fabrication and Testing
Your boiler was manufactured by HS Tarm , a world leader in hot water (hydronic) heating for over
80 years. The HS Tarm Bonus Plus Series boiler conforms to traditional high standards for quality
and reliability. It offers modern wood gasification technology with operating efficiencies at over 80%
when run properly. If treated properly and operated according to the guidelines in this manual it will
provide years of safe, dependable, and economical heating.
Bonus Plus boilers are designed and built in accordance with European Standard CEN 303-5. Safety
and performance testing and listing for U S markets have been performed by OMNI Test Laboratories,
Inc., Portland, Oregon. The boiler is tested and listed to applicable UL standards. The boiler is not
ASME stamped. The installer should follow local or state installation requirements.
The Bonus Plus wood gasification boiler is a log wood fired boiler designed and constructed for
highly efficient combustion of log wood. Do not burn other fuels in the Bonus Plus boiler. The Bonus
Plus
is not
a self contained weather-tight boiler. It should be installed within the heated building.
Bo-
nus Plus log wood boilers must be installed with a thermal storage system capable of absorbing
the complete output of the boiler during periods when the building is not calling for heat.
2.1.6 Models and Applications
The Bonus Plus model 30 is available with an output of 102,000Btu/hr (30 kW). Specification data for
the Bonus Plus is provided in Section 6.3.
The boiler can be utilized as a single heat source, or in parallel with another boiler. Residential and
non-residential applications are appropriate.
2.3 Fuels
Chemically treated or painted wood is unsuitable as fuel. The Bonus Plus boiler is designed for burn-
ing of cord wood only. Any species may be used, however, the wood must be properly seasoned and
with a moisture content below 25%. Wood should be split into pieces with a diameter of four to six
inches and stacked in a well ventilated, covered, indoor or outdoor space for at least one full year. A
traditional, covered, outdoor wood stack can work well, but may require more drying time. A wood-
shed is ideal. We recommend the use of a wood moisture meter to test the core moisture content of
your wood. Wood briquettes or manufactured pure wood logs can also be used as fuel provided they
have a minimum cross section of 2.5 sq in.
Manufactured logs should be at least 12” (0.25m) in
length. Excessively small and compact pieces of wood or wood pellets are not suitable. Coal cannot
be used as it becomes too compact and closes the combustion slot. The firebox can be filled to the
top.
Product Description and Requirements for Safe Operation > Boiler Fabrication and Testing