Boiler shows E13, the burner stops, and this may be associated with condensate issues on high-efficiency Slant/Fin boilers.

Safety: Turn off power. Condensate is mildly acidic; wear gloves and eye protection.

Steps:

• 1. Inspect condensate trap: Locate the clear or opaque plastic trap at the bottom of the heat exchanger. Remove and flush it with clean water to remove sludge and debris.
• 2. Check drain line: Ensure the condensate hose slopes continuously downward to the drain or pump. Straighten any kinks and clear blockages by flushing.
• 3. Condensate pump: If used, verify that the pump runs when the reservoir fills. Clean the pump reservoir and float mechanism.
• 4. Float switch: Confirm that the float switch wiring is intact and the float moves freely. Replace the switch if it sticks or fails continuity tests.

After cleaning: Reassemble, restore power, and reset the boiler. If E13 recurs, have a technician inspect for internal condensate path restrictions.