Goodman furnaces are heating appliances designed for use in residential homes. Like other gas furnaces, they are equipped with blower systems that cycle the warmed air through the ducts so it can warm the rest of the house. If you notice water leaking from your Goodman induced-draft blower, or ID blower, but you do not live in a very humid climate, something may be wrong with the way the furnace processes condensation.
Your first step should be narrowing down the leak source. Goodman furnaces take in air for both heating and combustion purposes. In winter months, ice or snow could be entering from these vents and leaking toward your blower system. If this is happening you need to invest in a snow cover for your vent and solve any other problem with ice buildup in your ductwork or venting system.
Gas and Condensation
Because Goodman furnaces have high efficiency ratings, they typically run all exhaust through a second processor that drains the heat and passes it into the house air. This also drains moisture from the exhaust, and this moisture needs somewhere to run. But if some furnace components are cracked, like the drain pipe, heat exchanger or reclamation pipes, this condensation may be dripping down onto your blower. Patch or replace parts as needed.
Another potential cause of blower leaks is a clog in your drains. The drain pan that siphons away condensation may not be cracked; but if it fills with debris, the water can eventually overflow and leak into other parts of the furnace. The same thing can happen further down, where your drain lines carry water away from the furnace entirely. Cleaning the drainage system and removing these clogs should solve the leaking problem.
Sometimes a leak in your furnace blower may not be related to the furnace at all. For example, if you have a humidifier installed further up in your ductwork, it could be creating the moisture and leaking back down on your blower. The same is true of heat pumps or other systems that may be producing leaks. If your furnace appears dry except for your blower, it may be time to check some of these other systems.