When parameter code number “35” is displayed on the face plate of the PFU760 module, follow this procedure to determine what caused this shutdown condition.
1. Loosen the two screws that hold the faulty module in its mounting position.
2. Pull the module out. It is not necessary to turn the electrical power off to the panel or modules.
3. Remove a working module and replace wit the suspected faulty module. CAUTION: Make sure green edges of the flame module line up with the top and bottom slots of its mounting location in the rack. Be careful not to bend the the pins located on the back of the module when handling the module and installing the module into its mounting location.
4. Restart the moved faulty module to see if the burner will start.
5. If the burner starts its trial for ignition and ignites the burner, then this will prove that the suspected faulty module is in good working order.
6. If the module does not start the trial for ignition and the number “35” is displayed, remove the module and check to see if fuse “F1” is open. The “F1” fuse is located on the right side of the module.
7. If the “F1” fuse is good, then the module is defective and needs to be replaced.
8. If the “F1” fuse is bad, replace the fuse with a 3.015 amp, slow acting fuse. Re-install the module into the relocated position.
9. If the burner starts its trial for ignition and ignites the burner, then this will prove the suspected faulty module is in good working order and does not need to be replaced.
10 Proving that the module was not defective, indicates a problem with either the ignition transformer, burner gas solenoid valve, burner air solenoid valve or the field wiring from the burner control module rack on the panel to these field devices.
11. Physically check the conduit and field devices for any type of visual abuse. Any broken devices or defective field wiring needs to be corrected on the suspected burner.
12. Before installing the suspected module back into its slot, disconnect the two wires that are attached to terminals 22e (burner air valve) and 16C (burner gas valve). These terminals are located on the back of the module rack.
13. Re-install suspected faulty module into its slot. Make sure that fuse “F1” is in working order.
14. Restart the burner. If code “35” is not displayed and the module attempts to light the burner, then the module is working properly.
15. Reconnect wire to terminal 16C and restart the module. If code “35” is not displayed, then the module, burner gas solenoid valve and its field wiring are okay.
16. If on restart code “35” is displayed and fuse “F1” fails, then the problem is a bad gas solenoid valve or faulty field wiring.
17. If item 16 does not occur, reconnect wire 22e and restart the module. If code “35” is not displayed and module attempts to light the burner, then the module, the burner air solenoid valve and its field wiring are okay.
18. If on restart code “35” is displayed fuse “F1 fails, then the problem is a bad air solenoid valve or faulty field wiring.