wff_ng_2 wrote:

>
> There are variations on this basic scheme. I'm presuming on pilotless
> (electronic) ignition ovens, this safety ensures that the main burner flame
> starts, rather than making sure the pilot is lit. If the main burner flame
> does not start, the gas to the burner would get cut off. I'd don't have a
> pilotless oven, but my gas furnace with electronic ignition works this way.

Electronic ignition systems usually use the electronic ignition to start a pilot
first.. The controls must sense that this pilot is started before the main gas
valve is opened. This is done so if for some reason their is an ignition
failure (low gas pressure, ignition system failure, whatever) that large amounts
of gas are not released while waiting a resonable time (usually 30 seconds) for
igntion to occur and it being sensed.

Once the immediate heating needs are met both the main and the pilot are shut
off until there is again a call for heat. This is the advantage of the system.
no standing pilot to waste gas when it is not needed.