Set Appliance State:

Mains Power Off
Ensure no demands
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Monitor the boiler display after mains power is turned on.
Does solid red lockout reoccur? How long does it take to appear?
LOCKOUT DOES NOT REOCCUR
LOCKOUT REOCCURS AFTER APPROXIMATELY 5 SECONDS
LOCKOUT REOCCURS AFTER APPROXIMATELY 15 SECONDS
Note:
Use ON/OFF switch to repeat test if necessary.
If solid red occurs after a significantly different time click HERE to use full diagnostic model.