B190 Enthusiasts

I also put this question under plumbing. I was not sure the proper placement of the topic. My question is on the functioning of the water heater. How does it turn on? It must be somewhat automatic. I just purchased my B190 and it worked fine on the last trip. I cannot get it to turn on now.
Any thoughts?
thank you,
Ralph

Hi - I've answered it under Plumbing, so let's keep all answers in one thread there for easy future reference.

Thanks.