Troubleshooting a Lennox Elite Furnace That Is Leaking Water

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Lennox Elite furnaces may leak due to a variety of problems.
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The Lennox Elite Series gas furnace product line offers high-efficiency heating for a wide range of home sizes. If you're currently experiencing water leakage from a Lennox Elite furnace, it may have several causes. Troubleshooting this malfunction can help pinpoint its cause, and provide insight into the best repair method.

Condenser Trap

Step 1

Disconnect power to the furnace by flipping the circuit breaker switch assigned to the furnace to the "Off" position.

Step 2

Locate a series of tubs coming from the bottom-left side of the Lennox Elite furnace. Remove the furnace door by unscrewing the screws with a Phillips-head screwdriver.

Step 3

Follow the primary black tube, which is larger than the surrounding hoses, to the condenser trap. The trap is a black box located directly inside the furnace. Review the seal from the drainage hose to the trap box. If you notice water dripping from the seal, you may need to repair the drainage hose seal.

Step 4

Disconnect the primary black drainage hose from the condenser trap by gently pulling the hose away from the trap. Point a flashlight down into the hose to review the hose quality. Over time, mineral deposits can accumulate in the drainage hose. If you notice an accumulation of debris along the interior hose walls, discard and replace. After replacing, turn on the furnace and monitor the hose to determine if this stopped the leaking.

Blower Box

Step 1

Turn off the electricity to the furnace by flipping the designated circuit breaker to the "Off" position. Remove the front panels located in the middle of the furnace by unscrewing with a Phillips-head screwdriver.

Step 2

Locate the blower box attached to the backside of the front panel. This box will be attached with insulation panels. Remove the panels using a Phillips-head screwdriver.

Step 3

Look inside of the blower box for water accumulation. Water may accumulate due to a broken silver bladder or faulty insulation. If there is water in the blower box, contact a professional repairman to replace the blower box and silver bladder.


If the condensing trap and blower box are dry, leaking water may be caused by a broken heat exchanger. If this is the case, a professional repairman must be called in, as removing and installing a heat exchanger is not a do-it-yourself project.

If your furnace has a built-in humidifier, turn off the humidifier and run the furnace; if there is no water leaking at that point, the problem lies within the humidifier.


Do not perform any troubleshooting steps while the furnace is still running, as the electrical parts pose an electrocution hazard.


Jonathan McLelland

Jonathan McLelland has been a professional writer since 2005. He has worked as a story writer and editor for the international sitcom, “Completing Kaden,” as well as a proposal writer for various production companies. McLelland studied communication and theater at St. Louis Community College.