Boiler failing to light most of the time. In order to troubleshoot I need to understand the lighting sequence.
Before sparking I assume the fan has to run and activate the pressure switch.
But I am confused over the next stage, if all is well, then the pilot light will ignite and next the main gas burners. But how does the system "know" that the pilot light has lit successfully, there appears to be no flame failure device you get on "open" flue systems. The pilot assembly consists simply of the pilot jet and the sparking electrode.
(PS It has been observed that the boiler will light when electric toaster is operating under the boiler. This is heating the bottom of the boiler and stuff inside. What is the significance).
Regards
Before sparking I assume the fan has to run and activate the pressure switch.
But I am confused over the next stage, if all is well, then the pilot light will ignite and next the main gas burners. But how does the system "know" that the pilot light has lit successfully, there appears to be no flame failure device you get on "open" flue systems. The pilot assembly consists simply of the pilot jet and the sparking electrode.
(PS It has been observed that the boiler will light when electric toaster is operating under the boiler. This is heating the bottom of the boiler and stuff inside. What is the significance).
Regards