Set Appliance State:
Mains Power Off
Gas Off
CH Demand
CH temperature control to maximum
DHW temperature control to minimum
CH temperature control to maximum
DHW temperature control to minimum
Attach U-gauge to gas valve outlet pressure test point
Gas On
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
Allow boiler to fire and run.
After approximately 90 seconds, burner pressure should increase to its set pressure.
Slowly turn the CH temperature selector anti-clockwise. As the temperature demand is satisfied, does the burner pressure reduce to its minimum setting?
Note: If CH burner pressure has been set at its minimum rate, then modulation will not take place.
When the U-gauge is removed, ensure the pressure test point is checked for soundness.
After approximately 90 seconds, burner pressure should increase to its set pressure.
Slowly turn the CH temperature selector anti-clockwise. As the temperature demand is satisfied, does the burner pressure reduce to its minimum setting?
Note: If CH burner pressure has been set at its minimum rate, then modulation will not take place.
When the U-gauge is removed, ensure the pressure test point is checked for soundness.
Isolate as per TOPs P4
and refit as necessary