Set Appliance State:
Turn Hot Water Tap On
Isolate Mains Power to appliance as per TOPs P4
Boiler On/Off Switch ON
Connect a U-Gauge to the Gas Valve outlet pressure test point
Boiler On/Off Switch ON
Connect a U-Gauge to the Gas Valve outlet pressure test point
| WARNING! Mains voltage is expected during test, follow TOPs P4 live testing procedure |
Measurement:
With the DHW Tap fully open and the DHW Temperature Selector (Potentiometer - see (1))
set to maximum, does the Burner ignite and operate at its maximum gas pressure of
approximately 34.2 mb?
Decrease the DHW Temperature Selector (Potentiometer) and if required decrease the
DHW flow from the tap.
Does the gas pressure modulate down to approximately 12 mb (35% of its maximum pressure indicating that
Stage 2 of the gas valve is closing) as water temperature increases?
Notes:
After initial lighting, if flow rate is adjusted to approx 3 l/min at the tap, time taken for this test will be reduced.
When U-gauge is removed pressure test point should be tightened & checked for gas soundness.
set to maximum, does the Burner ignite and operate at its maximum gas pressure of
approximately 34.2 mb?
Decrease the DHW Temperature Selector (Potentiometer) and if required decrease the
DHW flow from the tap.
Does the gas pressure modulate down to approximately 12 mb (35% of its maximum pressure indicating that
Stage 2 of the gas valve is closing) as water temperature increases?
Notes:
After initial lighting, if flow rate is adjusted to approx 3 l/min at the tap, time taken for this test will be reduced.
When U-gauge is removed pressure test point should be tightened & checked for gas soundness.
Isolate as per TOPs P4
and refit as necessary