Why Is My Furnace Leaking Water?

Your furnace may be leaking water at the base because there’s an issue with the furnace’s condensate drain system, a common problem in high-efficiency furnaces.

It’s a small problem that can cause huge damage to your furnace if it’s not fixed. So get a local Minnesota technician to fix it ASAP.

That’s the basics of what you need to know. But if you want to become more informed, read on.  

We’ll explain:

  • How a furnace can create water 
  • What causes that water to leak out of the furnace
  • Other issues that can cause water to pool around the furnace

What causes a furnace to create water

High-efficiency furnaces (those with 90% AFUE or higher) create water when they run. That’s why they’re called “condensing furnaces” because they produce condensation.

But why do they do that? 

Well, high-efficiency furnaces have 2-3 heat exchangers instead of one. This allows the furnace to extract more heat from combustion gases, cooling them down and condensing into water (condensation).

Normally, your furnace drains the condensation out of your home through a condensate drain line

However, that water can end up on the floor because of these problems...

Causes of a condensate leak

A clogged drain line
A clog in the PVC drain line will cause the water to back up into your home. Many homes have secondary drain lines, but they can become clogged as well.

Breaks in the condensate line
No brainer here. If there’s a leak in the line, expect to see water on the floor.

Malfunctioning condensate pump
Some furnaces need a pump to force the condensation outside. If the pump busts, the water will build up and leak out the furnace. 

More reasons water may pool near your furnace

Humidifier problems
Do you have a whole-home humidifier? The water could be coming from the humidifier next to your furnace rather than the furnace itself. 

Incorrectly-sized exhaust vent
Standard furnaces exhaust gases out a metal exhaust pipe called a flue. When the flue is incorrectly sized, hot exhaust cools down and condenses in the pipe, draining back to the furnace and leaking out.

Have a professional diagnose and fix your leaking furnace

Like we said, you’ll need a technician to fix this problem. Contact On Time Service Pros for a furnace repair

We serve the Hastings, Apple Valley, Burnsville, Cottage Grove, EaganWoodbury, Lakeville, Rosemount, Stillwater, the Twin Cities and more with quality HVAC service.

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