9.2
Protection function
AUTOMATIC INTERNAL FROST FUNCTION
Boiler automatic
frost function
(monitors internal boiler
primary temperature)
PUMP OVERRUN FUNCTION
End of boiler demand
(central heating or
domestic hot water)
PUMP ANTISEIZE FUNCTION
No central heating
demand after
a 24hr period
Fig. 94 Protection function
6 720 821 670 (2018/06)
Internal boiler
temperature
between
8°C & 5°C
Internal boiler
temperature
below 5°C
Pump runs for 3 minutes
to dissipate heat from
the boiler into the system
Pump runs 5 seconds
A central heating demand
every 24hrs from
last time pump ran
Internal boiler
Pump runs
temperature
rises above 9°C
Internal boiler
Central heating
temperature
demand is activated
rises above 25°C
activated, pump runs
normally
OPERATIONAL FUNCTIONS
Pump switches off
after a 3 minute
overrun period
Central heating
demand switches
off
Pump switches off
after a 3 minute
overrun period
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