Brochure
BUDERUS
Cast Iron Boilers
G215 – G315 Series
Residential Thermostream boilers
These Buderus boilers can be shipped fully assembled or the G315 can be shipped
knocked down. This option makes the G215 and G315 models ideal for everything
from the most straightforward new-home installations to challenging refurbishments
of vintage homes. To increase efficiency the boilers are designed with precision
made sectional construction as well as a unique “tongue and groove” design for
flue side sealing. With this distinctive construction the boilers are sealed gas tight,
eliminating lost heat. This dramatic increase in boiler efficiency affects a similarly
impressive decrease in your heating costs.
The attractive blue enameled jacket hides a full 3" of thermal insulation and flexible
GL-180M cast iron with silicone “barrier skin.” To streamline the appearance of the
boilers, the supply and return connections are located at the rear of the G215 and
G315 models. These boilers have minimal stack losses and increased efficiency;
they are for hot water space heating use and operate with either oil or gas.
Whether you heat by baseboard, panel radiators, hydro-air systems or radiant
flooring, our advanced heating systems will provide many years of exceptional
comfort and economy.
A better way to heat your home
Buderus Thermostream boilers are designed and built to the highest industry
standards. They extract and deliver more heat from every fuel dollar. Acknowledged
as the leader in high-efficiency, low-emission hydronic heating, Buderus offers
innovative design, quality manufacturing, exceptional efficiency and performance.
A Thermostream boiler is ideal for new installations or as a replacement for
virtually any make or model of boiler. This innovative technology eliminates thermal
shock, increases product reliability and lowers heating costs. The G215 and
G315 are compatible with most hot water tanks and offer a variety of convenient
installation options. Constructed with superior materials and designed by the
industry’s top engineers, a Buderus Thermostream boiler is an ideal choice for any
residential installation.
Thermostream design
The Buderus developed Thermostream Principle
for cast iron boilers, is proven to improve system
reliability and increase efficiency in heating
systems for any size home. Cool return water
mixes internally and is preheated with supply
water before being exposed to directly heated
surfaces. This process eliminates the risk of
damage caused by thermal shock, “hot and cold
spots” developing. The Thermostream design
allows for continuous low temperature operation
under normal conditions without maintaining a
minimum boiler temperature. Superb reliability
through excellence in product design!
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Design benefits
❚ Eliminates “hot and cold spots” in
the boiler
❚ Minimizes stresses normally caused
by rapid temperature changes
❚ Operates at low return water
temperatures
❚ Balances water flow through all
boiler sections








