INSTALLER
34
TAU UNIT
condensing boilers are equipped with an
electronic frost protection system. This system starts up
the boiler if temperature drops below a certain threshold.
CH FROST PROTECTION
FLUE GAS VENT AND COMBURENT AIR INTAKE
TAU UNIT
condensing boilers are open systems
belonging to class B23. They must therefore be installed
in proper boiler rooms. All the standards applicable to
this type of installation must be respected.
Vents and intakes must be made in conformity to appli-
cable national, regional, and local standards. (In Italy
refer to UNI - CIG 7129/92 standard).
The combustion gases are cooled to a temperature near
that of the central heating return before they leave the
boiler body. This makes it possible to use plastic flue
pipes instead of metal ones, with significant savings in
overall installation costs.
To protect the vent pipes against possible damage,
TAU
UNIT
boilers are equipped with a flue gas temperature
thermostat (as required by European standard EN 677).
b
Use of a high head fan allows the vent pipes to
reach lengths of up to 20 metres.
b
Caution! Do not connect the vent flue directly to
existing flues used to serve other appliances (cook-
ers, other boilers, etc.). Larger disused flues can
nevertheless be used as ducts for routing the boil-
er's intake and vent flues.
b
If the vertical section of vent flue is over 4 metres in
height, a condensate drain must be provided at its
bottom. This drain point must be connected to the
boiler's own condensate collection tank described
in the "Draining the condensate" section.
b
The horizontal sections of the vent flue must slope
down to the boiler at a gradient of at least 3%.
b
No special anti-frost additives are therefore needed,
unless the system is to be completely shut down for
an extended period of time.
b
If you do use anti-freeze in the system, make sure
that it is of the type that does not attack steel.
