Worcester Highflow 3.5 OF Installation And Servicing Instructions page 24

24
START.
ELECTRICAL MAINS
SUPPLY OFF
TURN ON GAS SUPPLY AND CHECK
FOR GAS DOES PIEZO IGNITER
PRODUCE SPARK AT Pll.Oli
YES
CAN PILOT BE LIP
YES
DOES PILOT STAY ALIGHT'
YES
SWITCH THE 3-POSITION SWITCH TO
THE HW SETIING. ON UNITS FITIEO
WITH A PROGRAMMER SET TO HW
ON CH OFF . IS THERE A LIVE
SUPPLY TO TERMINAL 1 BUT NOT TO
2'
YES
SWITCH THE 3-POSITION SWITCH TO
HW & CH. ON UNITS FITIEO WITH A
PROGRAMMER SET HW & CH
SELECT BUTTONS TO ON .IS THERE A
LIVE SUPPLY TO TERMINALS 1 & 2'
•
YES
ON MODELS FITIEO WITH A
PROGRAMMER SELECT EACH
AVAILABLE PROGRAMME IN TURN
WITH THE AID OF A
MULTIMETER. DOES THE
PROGRAMMER SELECT HW & CH
IN THE CORRECT SEQUENCE'
1.e HW ONLY SHOULD ENERGISE
TERMINAL 1 ONLY
HW & CH SHOULD ENERGISE
TERMINAL 1 & 2 ONLY
+
YES
SWITCH THE 3-POSITION SWITCH TO
HW & CH OR IF A PROGRAMMER IS
FITTED SET HW & CH TO ON
TURN HOT WATER AND HEATING
THERMOSTATS TO MAXIMUM DO
THE FOUR POLE RELAY CONTACTS
CLOSE'
YES
DOES THE CIRCULATING PUMP RUN'
YES
TURN THE HOT WATER PRIORITY
THERMOSTA TFULL Y ANTI
CLOCKWISE UNTIL IT CLICKS TURN
THE ROOM THERMOSTAT, IF FITTED,
TO MAXIMUM DOES THE WATER
DIVERTING VALVE OPEN'
NOTE. BEFORE CHANGING ANY
COMPONENT INDICA TEO IN THE
FOLLOWING GUIDE IT IS ESSENTIAL
THAT THE ASSOCIA TEO WIRING IS
CHECKED FOR CONTINUITY AND
CORRECT ROUTINE
NO
NO
NO
CHANGE SPARK IGNITER
CHECK E.C.O CONNECTIONS AT THE
THERMOCOUPLE AND GAS VALVE
FOLLOWING PROCEDURE 5 IN THE
MUL TIMETER HANDBOOK MINIMUM
CLOSED CIRCUIT VOLTAGE B mV
DOES PILOT STAY ALIGHT'
YES
IS THERE A LIVE SUPPLY TO OTHER
TERMINALS'
YES
I
REPLACE 3-POSITION SWITCH OR
PROGRAMMER
•
I
REPLACE 3POSITION SWITCH OR
PROGRAMMER
REPLACE PROGRAMMER
NO YES
H
IS THERE A LIVE SUPPLy TO
r r - I I S THERE A LIVE SUPPLY AT
TERMINAL4'
TERMINAL 5'
NO NO
NO
utLACE HOT WATER PRIORITY
I
REPLACE HOT WATER LIMIT
ERMOSTAT DO THE RELAY
THERMOSTAT
ONTACTS CLOSE'
YES
pEs
NO
IS THERE A LIVE SUPPLY TO
~--r-1
REPLACE CIRCULATING PUMP
TERMINAL 10'
NO
~LACE
PUMP OVERRUN CIRCUIT
NO
DES CIRCULATING PUMP RUN'
YES
~THE
RELAY CONTACTS OPEN>
YES
~n
IS THERE A UVE SUPPLY TO
TERMINALS'
NO NO
I
I
I
I
18. FAULT FINDING
DISCONNECT THE OVERHEAT THERMOSTAT
AND RECONNECT THE THERMOCOUPLE
ODES THE PILOT STAY ALIGHT>
IS THE CLOSED CIRCUIT VOLTAGE INCREASED?
YES
YES
~-
:{ REPLACE RELAY
I
NO
YES
h-f
REPLACE WATER DIVERTING VALVE
NO
NO
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