Water Heater Install - Electrical

I have two black cables comming out of my wall that was connect to an old water heater. They have no markings on them tell me which is hot and neutral. There is no ground wire. The voltage across the two black wires it 240V. The water heater I am installing is 240V. So I am good there. On the new water heater there is a red cable and a black cable. My question is: Can I connect either black cable comming out of the wall to the red cable on the hot water heater? I know there should be a white and a black comming out of the wall, but there isn't. If I have to use a specific Black cable comming from the wall, how do I tell which one?
Thanks
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Call the man...
There is no neutral on a 220 volt circuit. Each of the two black wires comming out of the wall will be 120 volts to the neutral and also to the ground back at the fuse/breaker box. There should be a green or bare wire for the ground. This may not be in some older houses.
Out of the water heater you connect the black wire to one of the black wall wires and the red wire to the other black wire. It does not make any differance as to which of the balck wall wires you use for either of the water heater wires.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.