Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Turn Hot Water Tap On
Attach U-gauge to burner pressure test point
DHW temperature selector set to MAX
Gas On
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Allow burner to ignite and establish.
Set the maximum DHW pressure as per the table by rotating the plastic nut (7mm) while holding the back nut (9mm) in place until the correct pressure is obtained (Clockwise to increase, anticlockwise to decrease).
Notes:
Minimum pressure should be checked once adjustment is complete.
When U-gauge is removed test point should be checked for gas tightness.
For Wickes 90 use values for Finest or Finest Propane depending on gas type.