Cause of error code 2

Boiler Safety Limit Open

Boiler Safety Limit wired to terminals J6-1, 2 or 3 OPEN:
-Thermal Fuse Switch contact open.
-Air Pressure Switch contact open.
-Auto Reset High Limit contact open.

Solution for error code 2

-Loose wiring to limit device.
-Auto Reset Supply high limit sensor detected temperature in excess of 200°F.
-Defective Auto Reset Supply High Limit Switch.
-Thermal Fuse Switch blown due to temperature rise above 358°F.
-Air Pressure Switch contact open - check for blocked vent/air intake.
-See possible causes for “Hard Lockout 4”.

NOTE

Block Vent Special Note
Before a call for heat the air pressure switch is closed.  When there is a call
for heat with a blocked vent the air pressure switch will open (due to excessive pressure of the blower against a blocked flue pipe) after the blower starts. The control stops the start sequence and stops the blower.  After the blower stops the pressure switch re-closes and the cycle continues.  The displays shows the cause of trip for only the time the pressure switch is open.