When most homeowners think of a water leak, they tend to think of water leaking from a burst pipe, a faulty appliance, or a cracked water heater tank. Most would never imagine that their gas furnace could be a potential source of leaking water. However, gas furnaces actually produce a fair amount of water, so leaks are not unheard of. By having a better understanding of how gas furnaces work and why they sometimes leak, you can more quickly diagnose a leaky furnace in your home.
Is it a Leak or Condensation?
First of all, if you notice any water on or around your furnace, you shouldn't always assume that you have a water leak right away. Depending on the temperature inside your home as well as indoor humidity, it's possible that the water you're seeing is no more than harmless condensation produced by the unit itself. However, if the amount of water leaking is extensive (enough to drip on the floor), you may want to check your condensation tubing, which runs from the furnace to the floor or wall, to make sure there isn't an obvious leak.
A Humidifier Problem
Your gas furnace may also be equipped with a humidifier, which adds much-needed moisture to your home and keeps the air comfortable. Unfortunately, furnace humidifiers can develop leaks over time--and because these components are often housed inside the furnace itself, the leak may not become obvious until it has gotten much worse. Having regular tune-ups on your water heater is the best way to be alerted of a humidifier leak early and to avoid more extensive repairs or damage to your unit.
A Clogged Drain System
All gas furnaces also have a drain, which usually runs to the floor or wall and is shared with your home's air conditioning system. Over time, this drain pipe can become clogged with debris from either unit. Eventually, the clog could prevent water from passing through and draining properly, resulting in puddling on your floor near the furnace itself and potential damage to your floors or other nearby materials.
The good news is that most causes of a furnace water leak can be prevented with regular maintenance and tune-ups on your home's heating system. If you do experience a leak, however, it's important to have the issue addressed and repaired by an experienced furnace specialist. This way, you can be sure the repair is done correctly.