6.8.3 Troubleshooting the 24 VAC Circuit in FBRA18 Units (Continued)
A
Is 24VAC
present on N/O terminal of latch relay?
NOTE: All voltage measurements involving the gas valve leg of the 24V circuit must be made within 4 seconds of unit calling for heat. If unit does not fire within 4 seconds, ignition modules will lock out and controller must be turned off then back on to reset.
Probable causes are failed
No24V transformer or failed wiring between transformer box and
component box.
Yes
Is 24VAC
present on COM No terminal of latch
relay?
Yes
Is 24VAC
present on J1 pin No 3?
If 12VDC is applied across coil, probable cause is failed relay. If not,
probable cause is failed wiring between controller and latch relay or failed
controller.
Probable causes are failed wiring between terminal block and computer, or failed computer.
Yes
When water level |
|
|
is above lower water level | No | Go to |
sensor, is CYCLE LED lit? |
| "C". |
Yes |
|
|
Go to |
|
|
"B". |
|
|
