Glow-worm SwiftFlow 120 Servicing Instructions page 15

If a mains potential room thermostat is connected, ensure that the switch live is connected to PIN 1 in the
5 pole connector.
Check continuity of clock/timer harness, ensure an electrical supply is available, ensure that remote
controls are calling for heat.
Isolate the boiler from electrical supply, remove outer case.
YES
Switch on electrical supply, is there a display
on clock/timer?
YES
Disconnect and insulate the purple cables
from heating common and heating on.
YES
Advance clock/timer until a demand is indicated
Is there now continuity between heating
common and heating on?
YES
Clock/timer in order if no central heating,
refer to main fault finding.
DIGITAL CLOCK/TIMER STYLE 1 and 2 FAULT FINDING
If a mains potential room thermostat is connected, make sure that the switch line is connected to pin 1 in
Check continuity of clock harness, make sure an electrical supply is available make sure that remote
Does clock keep time
Yes
Isolate electrical supply set clock to on period
Is there continuity across
common and heating on
Yes
Set clock to off period. Is there continuity
across common and heating on
ELECTRO/MECHANICAL CLOCK/TIMER FAULT FINDING
Supplied By www.heating spares.co Tel. 0161 620 6677
3 F a u l t F i n d i n g
NO
NO
CLOCK FAULT FINDING
the 5 pole connector.
controls are calling for heat.
Make sure the override switch if fitted is in the "
No
" position
No
Clock in order if no
central heating refer to
main fault finding
No
15
Faulty clock/timer.
Replace.
Faulty clock/timer.
Replace.
Diagram 3.9
Faulty clock
replace
Yes
Diagram 3.9
221045A