Precedent Electromechanical Ignition Board Info and Troubleshooting Tips

Troubleshooting Tips:

1. The flame rod circuit is energized (with 110 vac) anytime the board is powered up.
2. The voltage on the flame rod circuit drops to 90 vac on trial for ignition.
3. There is no 24 vac on P1-9 (powering the Rollout Switch, Pressure Switch and TCO1 & TCO2) until there is a call for heat.
4. You can bypass the Pressure Switch (for troubleshooting purposes) by waiting until the board gives you a (3) flash before jumping out the Pressure Switch. (You can wait up to 60 seconds after the (3) flash to jump the switch)
5. If you take away the “W1” call and reapply it, you will have to repeat step 4. (Because the board checks the Pressure Switch circuit to make sure the switch is not closed before the Combustion Blower Motor starts)
6. A “W1” & “W2” simultaneous call (such as “W1” and “W2” jumped together) gives you Low Fire for 10 minutes before transitioning to High Fire.
7. You do not need a “G” call with a “W1” call (the board will automatically turn on the fan 45 seconds after proving flame)
8. If you do give a “G” call with a “W1” call the indoor fan will come on immediately.
9. You do not need a “G” call with a “Y” call (the board will turn on the fan immediately with a “Y” call) this makes sense so the economizer (if installed) will work.
10. You can change the Indoor Fan off delay with the on-board jumpers. Options are;
    1. 90/60 seconds for heat.
    2. 80/0 seconds for cool.
    3. No jumpers installed defaults to the lowest number (60 seconds heat, 0 seconds cool)
11. If the board will not prove flame;
    1. Make sure the (Load Side) common wire of the 24 vac transformer (the transformer powering the board) is connected to sheet metal ground.
    2. Make sure the flame rod is clean, no rust or carbon build-up.
    3. Make sure the flame rod (and or) the wire going to the flame rod is not shorted to ground

List of LED Flash Codes

OFF = No power to board or bad board if there is 24 vac is measured from “R” to “B”

ON = Normal No call for heat

STEADY FLASH = Call for heat

(2) Flash = 1 Hour Lockout

(3) Flash = Pressure Switch

(4) Flash = TCO Open

(5) Flash = Flame W/O Gas (the board is sensing flame but is not powering the gas valve)

(6) Flash = Rollout Switch Open

(7) Flash = W1 / W2 Swapped (W2 call before W1)

LED Flash Code Notes:

1. The board tries (3) times to prove flame and then will lock out (with a (2) flash)
2. If the TCO circuit opens, the board will energize the Indoor Fan immediately.
3. If you have a true (5) flash condition (flame sensed w/o gas) the board will turn on the Indoor Fan immediately.
   1. If there is a (5) flash code and the indoor fan is not on, it is a bad board.
   2. If there is a (5) Flash code and there is no flame present, it is a bad board.
   3. A Flame Rod shorted to ground does not generate a (5) flash code.

WARNING:

Information in this article is intended for use by individuals possessing adequate backgrounds of electrical and mechanical experience and who comply with all federal, state, and local laws, rules, orders, or regulations related to the installation, service, or repair of a heating or central air conditioning product. Any attempt to install, service, or repair a heating or central air conditioning product may result in personal injury and/or property damage. The manufacturer or seller cannot be responsible for the interpretation of the information contained herein, nor can it assume any liability in connection with its use.