A few yrs. ago I had a client that had a dual fuel boiler. Natural gas and fuel oil.
We ran it on natural gas normally, but he had a buried tank w/ some fuel oil he wanted to burn.
We changed a few settings and fired it up.
Wow, what a difference in output. I’d forgotten how much hotter oil burns v natural gas.
Was this using the same burner tips for the drastically different fuels?