I've seen it suggested that the Suprima gas valve has two coils but I can't find any detail on how it works.

I wondered if one is for start and one for run?

Our boiler is lighting, but then immediately dropping out - as if it's not detecting a flame. However once it's running it's fine until it reaches temp. If there was an intermittant flame detection issue I'd expect the drop-outs to be much more random.

Any thoughts welcome.