That is quite so but that testing idea was thought up for normally on boiler pilot lights.
I would say that it is very important on a hob that they do not stay on without a flame.
But I am still suspicious of the OP's assessment that all four are failed to on!
I would say that it is very important on a hob that they do not stay on without a flame.
But I am still suspicious of the OP's assessment that all four are failed to on!