H120 –H150 Hot Water Boilers
page 15
5.3.4 OPERATION
Sequence of events once the boiler has been correctly installed with the room thermostat and burner
turned off.
Event
Result
Turn on electrical power to the boiler
Controller powers up and completes test procedure.
Pump starts up. Flow indicator on.
Turn on room thermostat
Turn controller on.
Ignition sequence begins; checks water flow, high limit
and flow temperature against set temperature.
Burner lights.
Burner indicator on.
Water flow reaches set temperature.
Burner turns off.
Water flow temperature falls 5
°
C
below set temperature.
Burner relights.
Burner indicator on.
Water flow temperature reaches 100
°
C
High limit switch opens, burner shuts down. Pump
continues to run.
Controller turned off
Burner shuts down, pump continues to run.
Room thermostat switches off
Burner shuts down, pump continues to run till water
temperature drops to 40˚C.
Room thermostat switches on
Pump restarts, burner ignites.
Water flow stopped by external control
Flow switch de-activates, burner turns off and pump
continues to run.
Flow indicator off.
Water flow is reinstated
Flow switch reactivates, burner re ignites.
Flow indicator on.
6.0 GAS CONVERSION
6.1 BURNER CONVERSION
Gas type burner conversion
•
Turn off the gas at the external gas valve and turn off the power.
•
Remove the access panels from all available sides.
•
Disconnect internal gas pipe from inlet side of gas valve.
•
Remove the four screws holding the burner assembly in position.
•
Disassemble burner tray and remove ribbon burners to expose burner injectors.
•
Remove burner injectors and replace with the correct sized injectors for the gas.
•
Remove regulator screw cap from top of gas valve.
•
Turn plastic plug anti-clockwise until fully removed and withdraw spring.
•
Insert spring for desired gas type and re-install plastic plug.
•
Re-install burner assembly and reconnect gas supply make sure all gas joints are tight
and the earth screw is replaced.
•
Check gas system for leaks.
•
Commence lighting procedure as described above.
•
Adjust burner pressure as described above.
