Be very careful here.
Does the hob have a flame failure device?

Not sure about the hob, but i`m pretty certain the oven does

If not, you have the risk that a burner on a low simmer setting could
go out when the boiler fires up, leading perhaps to your rapid exit
through one of the windows surrounded by the remainder of your house.
I don't want to be melodramatic, but this should be checked.

I know what you`re saying... once lit the audible pitch changes but it
stays on quite happily.

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