I have an electric peak demand controller Econolog88 by Mitec installed in 1984. Recently instead of showing my kilowatt use, it shows 0.F on the digital display. I never had a manual. How can I get the display back? Does anyone else make a peak demand controller if it needs to be replaced?

More than likely the display is a sympton of either a sensor failure or control board problem. After 16 years technology has changed quite a bit, and without a manual you won't have the tools to diagnose the system. Depending on what you need to control there are many manufacturers that make new controllers which will suit your needs. What is it you are controlling... what is the scenario? Honeywell made a load controller which worked well in the 80's but no longer available and parts just aren't made anymore to repair it.