Glow-worm COMPACT 80p Instructions For Use, Installation & Servicing page 30

With the boiler cold, check connections of the thermocouple, boiler overheat cut-off and gas valve.
Disconnect overheat cut-off connectors at points A and B at the gas valve, see diagram.
Test continuity of the overheat cut-off. Is there continuity?
YES
Re-connect boiler overheat cut-off to points A and B.
Disconnect thermocouple at point D of the gas valve.
Test continuity between point C and the body of the
gas valve. Is there continuity?
NO
Test continuity of thermocouple between inner
point D and point E. Is there continuity?
YES
Thermocouple and boiler overheat circuit satisfactory.
GAS
CONTROL
VALVE
THERMOCOUPLE FAULT FINDING
221679H
Supplied By www.heating spares.co Tel. 0161 620 6677
13 Fault Finding
BOILER
OVERHEAT
CUT-OFF
CONNECTION 'C'
Faulty boiler overheat cut-off,
renew.
YES
Faulty cut-off connectors into
gas valve. Either at A or C.
Renew where faulty.
NO
Faulty thermocouple, renew.
CONNECTION 'A'
CONNECTION 'E'
CONNECTION 'D'
CONNECTION 'B'
30
NO
Diagram 13.5