Vaillant TURBOmax Plus SERIES Instructions For Installation And Servicing page 37

Thermostatic radiator valves
The boiler has a built in automatic
bypass valve making it ideal for use
in systems with thermostatic radiator
valves (no separate system bypass is
required).
For optimum fuel economy it is
recommended that where TRV's are
used they are used in conjunction
with a programmable room
thermostat or separate timer and
room thermostat to ensure complete
boiler shut down when the heating
demand is satisfied. (The radiator in
the room containing the room
thermostat should not be fitted with a
TRV).
Frost protection
The boiler has an integral frost
thermostat which is designed for
protection of the boiler.
To protect remote or exposed parts of
the heating system or property
additional frost protection measures
must be taken such as the installation
of an external frost thermostat. This
frost thermostat should be connected
across the boiler terminals 3 and 4,
in parallel with any external heating
controls.
Circulating pump
The boiler incorporates a built in
circulating pump that is fully prewired
(no additional wiring is necessary).
The pump incorporates an automatic
overrun period after the boiler
switches off.
BOILER INSTALLATION SEQUENCE
Anti-cycling 'economiser' control
The boiler incorporates a built in
anti-cycling control to ensure that
energy wasteful short cycling of the
boiler cannot occur. This control
prevents the boiler from re-igniting for
a preset period of 5 minutes after
central heating operation (the hot
water operation is unaffected by this
control and hot water can be drawn
at any time).
Note: To temporarily override the
anti-cycling control turn the main
boiler on/off switch to the off
position „0" and then back to the on
position „I" after a few seconds.
Automatic pump spin control
(APS)
The boiler incorporates a built in
control which will spin the built in
circulating pump and operate the
diverter valve (TURBOmax only) once
in a 24 hour period. This control
helps to prevent seizure when the
boiler is not operated for a period of
time. This control is not active when
the power supply to the appliance is
turned off.
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