Worcester Gas boiler

BOILER FUNCTION
6 720 645 222a (2012/05)
18
7.3 PROTECTION FUNCTION
Fig. 22 Protection function
Internal boiler
temperature
between
8°C & 5°C
Boiler automatic
frost function
(monitors internal boiler
primary temperature)
Internal boiler
temperature
below 5°C
Internal boiler
temperature
rises above 9°C
Pump runs
Pump switches off
after a 3 minute
overrun period
Internal boiler
temperature
rises above 12°C
Central heating
demand switches
off
Pump switches off
after a 3 minute
overrun period
Central heating
demand is activated
Pump runs for 3 minutes
to dissipate heat from
the boiler into the system
End of boiler demand
(central heating or
domestic hot water)
AUTOMATIC INTERNAL FROST FUNCTION
PUMP OVERRUN FUNCTION
A central heating demand
activated, pump runs
normally
Pump runs 5 seconds
every 24hrs from
last time pump ran
No central heating
demand after
a 24hr period
PUMP ANTISEIZE FUNCTION
6720643895-111.1Wo