Honeywell RM7800 Tech Tip.

Honeywell RM7800 Tech Tip.
04/18/2018

The power LED on the 7800 Series control is blinking. What does this mean?

A slow blink, off every 2 to 3 seconds, is an indication that the control is running its self-tests and operating normally.

If the power LED is on steady or a blinking rapidly it indicates the controls micro has failed and the control needs to be replaced.  This will result in the display giving a message of “waiting for connection” due to the fact the micro is no longer working and unable to communicate with the display.

With the Enhanced models it can be a general/broad based indication of a fault code.  This is not the same as the display fault codes and only occurs when the control is in alarm – red alarm LED is on.

The fast blinks indicate the tens portion of the code and the slow blinks the ones portion of the code.  3 fast blinks followed by 2 slow blinks would indicate a code of 32.  Definitions of the “blink” codes can be found in the control specification sheet.