Pressure Switch Failed to Close
The blocked vent pressure switch contacts have opened. Check to make sure the venting system is not blocked. Check to make sure the condensate drain is not clogged and is sloping toward the drain. Make sure the vent length does not exceed the specified limits. Make sure the vent terminal is not blocked. Check to make sure the pressure switch tubing is clear. Replace the pressure switch if the venting system has checked out O.K. Control will reset once problem is corrected.