22
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Subject to change due to technical improvements
Approval, antifreeze, pressure equalisation, venting
Approval
Every heating system must be approved.
Inquire at you building authority and ask your
chimney sweep.
Operation only by trained personnel
The system may be operated only by trained
personnel. Instruction can be given by the heating
installer or our customer service. Please read this
user manual to be assured of avoiding errors in
operation and maintenance of the boiler.
Children must be kept away from the boiler
room and pellet store.
Antifreeze
If a house with average insulation is unoccupied
in winter at low temperatures for more than fi ve
days, check once a week (twice a week for very
low temperatures) to make certain that the boiler is
operating properly.
If the building is unoccupied in winter for longer
intervals, up to 30% antifreeze can be added
to the heating water. To compensate for the
disadvantage of reduced heat capacity and
increased fl ow resistance, only slightly higher fl ow
temperatures are needed.
Insulate contact sensors
If the pipe in the vicinity of a contact temperature
sensor is not insulated (e.g. in externally installed
heating circuit groups), lower than actual
temperatures will be measured. For this reason,
pipe insulation may not be recessed or weakened
for heating circuit fl ow sensors. For uninsulated
piping systems, the measurement area must be
insulated with mineral wool at least 20 mm thick
over a length of at least 20 cm of pipe.
Pressure equalisation
For pressure equalisation in the system, a
diaphragm expansion tank with a gross capacity of
around 10% of the system volume is needed (see
conditions for guarantee and warranty).
An 18-litre expansion tank is already installed
on the PU 7-15t boiler. This is enough for typical
underfl oor and radiator systems. If there is a buffer
storage tank, an additional expansion tank is
needed.
All shut-off valves along the path from the
expansion tank to the boiler and to the buffer
storage tank must be capped valves, or the hand
wheels or levers must be removed from the valves
(hang on the valve with a wire) to ensure that they
cannot be closed by accident.
If the pressure difference between cold and warm
heating system (buffer fully loaded if installed)
is greater than 1.0 bar for a single-fl oor system
or 0.5 bar for a three-storey system, then the
expansion tank is too small and absolutely must
be replaced with a larger one. If the installed
expansion tank is not large enough, the system
sucks in air when cooling and the air is absorbed
by the cold water and transported to the boiler.
At the point of highest temperature, the air
separates from the water again. This is the usual
situation in the boiler, and the inevitable result
is that the boiler wall will rust through at these
places.
Venting
Automatic venting valves in the boiler outlet, at
the highest point in the distribution network and
at the top of the buffer signifi cantly reduce the
danger of rust and also the frequency of radiator
venting.
Approval, antifreeze, pressure equalisation,
venting
Approval
Every heating system must be approved.
Inquire at you building authority and ask your
chimney sweep.
Operation only by trained personnel
The system may be operated only by trained
personnel. Instruction can be given by the heating
installer or our customer service. Please read this
user manual to be assured of avoiding errors in
operation and maintenance of the boiler.
Children must be kept away from the boiler
room and pellet store.
Antifreeze
If a house with average insulation is unoccupied
in winter at low temperatures for more than fi ve
days, check once a week (twice a week for very
low temperatures) to make certain that the boiler is
operating properly.
If the building is unoccupied in winter for longer
intervals, up to 30% antifreeze can be added
to the heating water. To compensate for the
disadvantage of reduced heat capacity and
increased fl ow resistance, only slightly higher fl ow
temperatures are needed.
Insulate contact sensors
If the pipe in the vicinity of a contact temperature
sensor is not insulated (e.g. in externally installed
heating circuit groups), lower than actual
temperatures will be measured. For this reason,
pipe insulation may not be recessed or weakened
for heating circuit fl ow sensors. For uninsulated
piping systems, the measurement area must be
insulated with mineral wool at least 20 mm thick
over a length of at least 20 cm of pipe.
Pressure equalisation
For pressure equalisation in the system, a
diaphragm expansion tank with a gross capacity of
around 10% of the system volume is needed (see
conditions for guarantee and warranty).
An 18-litre expansion tank is already installed
on the PU 7-15t boiler. This is enough for typical
underfl oor and radiator systems. If there is a buffer
storage tank, an additional expansion tank is
needed.
All shut-off valves along the path from the
expansion tank to the boiler and to the buffer
storage tank must be capped valves, or the hand
wheels or levers must be removed from the valves
(hang on the valve with a wire) to ensure that they
cannot be closed by accident.
If the pressure difference between cold and warm
heating system (buffer fully loaded if installed)
is greater than 1.0 bar for a single-fl oor system
or 0.5 bar for a three-storey system, then the
expansion tank is too small and absolutely must
be replaced with a larger one. If the installed
expansion tank is not large enough, the system
sucks in air when cooling and the air is absorbed
by the cold water and transported to the boiler.
At the point of highest temperature, the air
separates from the water again. This is the usual
situation in the boiler, and the inevitable result
is that the boiler wall will rust through at these
places.
Venting
Automatic venting valves in the boiler outlet, at
the highest point in the distribution network and
at the top of the buffer signifi cantly reduce the
danger of rust and also the frequency of radiator
venting.