Hard Lockout 4: Supply High Limit

Condition

• Sage supply sensor detected
• temperatures in excess of 210°F.

Possible Cause

• Heating load at time of error was far below the minimum firing rate of the boiler.
• Defective system circulator or no flow in system piping.
• Improper piping – See boiler piping diagram:
  Heat Only / Heat & DHW1 / Heat & DHW2
• Defective boiler circulator, no flow or insufficient flow in boiler loop.
• Control system miswired so that the boiler operation is permitted when no zones are calling.