Condition
- Boiler Safety Limit, or External Limit wired to terminals J5-1 OPEN:
- Jumper for External Limit wired to terminals 11 and 12 or device connected to external limit open
- Flow Switch contact open.
More Info: Troubleshoot “Limit String”
Possible Cause
- See possible causes for “Hard Lockout 4”.
- Loose wiring to limit device.
- External Limit defective or jumper not installed.
- If yellow light on LWCO is on, system is low on water.
- If neither yellow or green light is on, check LWCO harness.
- Flow Switch contact open – Check for adequate flow.
- Bad Flow Switch
