Worcester Greenstar Ri - Main Function; Boiler Operation Sequence; Protection System Functions

MAIN FUNCTION
NO
YES
PERMANENT
MAIN SUPPLY
TO BOILER
BOILER
DEMAND
FROM
SYSTEM
Fan to
start
speed.
Pump ON.
Prepurge
then ignition
spark
4 seconds
BLUE
LIGHT
ON
BURNER
LIT?
GREEN
FLAME
LIGHT
ON
Fan run
10 seconds
then re-spark
5th
attempt?
LOCKOUT
Stabalisation
then fan low
45 seconds
Fan (& gas)
modulation
to achieve
set
temperature
(35-82°C)
END OF
BOILER
DEMAND
Gas valve
OFF
Pump run 3
minutes
Fan run 30
seconds
Over temperature shut-
down if water tempera-
ture is 5°C above set
value.
Fan overrun
30 seconds
3 minute wait
Boiler temperature
below 8°C
Run autofroststat
function
PROTECTION SYSTEMS
Pump antiseize
Pump run 5 seconds
every 24hrs
NO
YES
MAIN FUNCTION
INSTALLATION & SERVICING INSTRUCTIONS FOR WORCESTER BOSCH GREENSTAR Ri
8 716 109 699a (05/05)
49
FAULT FINDING
& DIAGRAMS