CH IGNITION

Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4

CH Demand

Attach pressure gauge to gas valve outlet pressure test point
Selector switch to DHW and CH position
CH temperature selector to maximum
DHW Preheat selector to Off position
Ensure CH system is cool

Gas On

WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure

Mains Power On

Measurement:

Allow fan to run and ignition sequence to commence.
Does the burner pressure behave as described above?
Note: When pressure gauge is removed pressure test point should be tightened and checked for gas soundness.

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The burner will initially ignite at minimum pressure (approximately 2.5mb) it will then briefly ramp up to maximum pressure (approximately 12.2mb) before dropping back to minimum.
Over the next 10 -20 seconds it should then steadily ramp back up to maximum pressure.