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Honeywell flame control

LEF Member Posts: 3
We have a Honeywell flame control on an industrial burner. When we tried to start the burner we get a message "Standby hold: F/G (Flame Detected) The problem is that the burner was cold and there is no flame. What can we check for? how or why would the eye produce a flame signal with no flame? Or is one of the control modules bad?


  • icesailor
    icesailor Member Posts: 7,265

    If it is a 7800 Series Honeywell, one part of the control think it "sees" a flame and another part knows that there isn't a flame. I don't know what the burner has for a flame sensor, but if it isn't bad, the 7800 needs to be replaced. There is usually a troubleshooting ladder diagram that comes with a new control.
  • LEF
    LEF Member Posts: 3

    Flame control read 1.4v on the eye. Measured voltage on the eye wires @ 0.0, so the eye was ok. Replaced 7800 unit. everything works ok. Burner is running. Thanks.

    I presume that the 7800 unit is no good, but before I toss it I will keep it in a warm relatively low humidity environment for a few days to see if drying makes a difference.
  • LEF
    LEF Member Posts: 3
    7800 interchange

    the old unit was a RM7895 A 1014. I have a RM7823 A 1016. I can see the 7823 has no jumpers JR1-JR3 on the front, but no other visible differences. will these interchange ok? We have a spare in it today, but I am wondering if the RM7823 will work ok if I change the 3 plugin modules (timer, flame sensor and display (keyboard) modules)
  • icesailor
    icesailor Member Posts: 7,265

    Its my understanding that the numbers mean they have programs for different applications. An oil only might have different numbers than a gas only one. A Gas/Oil unit might be different than the other two. It often has to do with the timing of sequences. If you have access to a Honeywell Tradeline book, you might be able to figure out what your old 7800 does.

    Usually, when the burner won't start, the 7800is bad. I don't know if they are rebuildable.
  • Burnertech
    Burnertech Member Posts: 6
    False Flame

    Honeywell does state that you can use a lower or higher functioning 7800 series control, but the proper wiring changes must be made or the burner will not sequence.

    Your flame signal should be above 1.4v. If your burner is clean and combustion is set properly you may have a failing eye, or possibly a failing flame signal amplifier(flame card)

    Honeywell sends a great manual with each control that has a good troubleshooting and general information guide. If you don't have yours they are easily obtained online for free.

    If you don't mind me asking what type of burner is this attached to?