Is there an Eberspacher remote control unit that I can operate from my phone when I am away from my boat ?

Yes, Eberspacher do supply smartphone app systems to remotely control Eberspacher heaters. We would require to learn the exact model and build year of your heater to be able to advise on compatibility ... or perhaps if you could send a photo of your heater dataplate to sales@butlertechnik.com

Thank you