Set Appliance State:
CH Demand
Isolate Mains Power to appliance as per TOPs P4
Selector switch to heating and hot water position
CH temperature selector to maximum
DHW temperature selector to minimum
Attach U-gauge to gas valve outlet pressure test point
Selector switch to heating and hot water position
CH temperature selector to maximum
DHW temperature selector to minimum
Attach U-gauge to gas valve outlet pressure test point
| 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 (1) anti-clockwise.
As the temperature demand is satisfied, does the burner pressure reduce to its minimum setting?
Notes:
1. If CH burner pressure has been set at its minimum rate, then modulation will not take place.
2. 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 (1) anti-clockwise.
As the temperature demand is satisfied, does the burner pressure reduce to its minimum setting?
Notes:
1. If CH burner pressure has been set at its minimum rate, then modulation will not take place.
2. When the U-gauge is removed, ensure the pressure test point is checked for soundness.
Isolate as per TOPs P4
and refit as necessary