My water heater was broken and I traced it back to a problem with the power. I was only getting 50 volts for a 240v unit. I found this box connected between the 240v line from the fusebox and the water heater and I'd like to know what it's for. The 240v line is coming in just fine but breaks down to 50v when it comes out of the box and into the water heater. I can bypass the box completely but I feel like it's there for a reason.
I can't find anything written on the box or components that would help identify its purpose.
I had one on the out side of my house and it was also connected to the phone lines that book was used in the 70tes. Probably about the time your house was built. I took it out and every thing still works fine and that small box workers great for little junk you have on your bench.