I've got a museum ready off-peak meter that seems to not be turning on consistently. I'm able to track it after installing a whole-house energy meter that clamps around the incoming power lines. I can see a 3.5kw or so draw when it's working, but see days where it's not showing any draw, and those are the days the hot water is not so hot, or non-existent. It seems to me an intermittent failure in the heating element or temperature sensor is unlikely the culprit. Is there any way to get the meter itself tested? My understanding is it's activated by the power company injecting a control signal into the power feed to activate and deactivate it?