Electric or Gas Powered

[Kyle Scholnick]

How can you tell if anything in a condo unit is gas powered vs electric, such as the HVAC or water heater? I spoke with the electric company and they didn't know. Seems like this info is passed from seller to buyer for decades, but if seller can't be contacted, what is the best way to find out? 

What other utilities need to be serviced in a unit? Electric I got....trying to find out about gas via this post....water is included in HOA...what other utilities/service providers should I be checking for? Thank you.