If you have a high-efficiency furnace, it produces water as part of normal heating operation. When you find water around your furnace, we first look at the condensate drain, trap, and pump. If you have a standard-efficiency furnace, the furnace itself should not normally be producing condensate.
Before you assume your furnace is leaking water, look at where the water starts.
Identify What Kind of Furnace You Have
Look at the vent coming out of your furnace. High-efficiency furnaces commonly vent through PVC pipe and have a condensate drain. Standard-efficiency furnaces commonly use a metal flue.
If you're not sure which type you have, check the model information or have a technician identify it. Do not remove panels or take apart the venting to find out.
Clogged Condensate Drain or Trap
Your high-efficiency furnace has to send the water it makes to a drain. If your furnace condensate drain is clogged, water backs up in the drain or trap until it spills around the equipment.
Some systems have a safety switch that shuts the furnace down when condensate backs up. If you have water on the floor and the heat has stopped too, schedule heating repair so we can check the drain and find the blockage.
Failed Condensate Pump
Some systems send condensate into a small pump beside the furnace.
If the reservoir is full and the pump is not emptying it, we check the pump, discharge line, and power supply. Tell us what you see, but do not take the pump apart or bypass its safety switch.
It Might Not Be the Furnace
Before we open up the furnace, we look at the equipment around it.
Whole-home humidifiers are commonly mounted on or near the ductwork, so a leaking water connection, drain, or housing leaves water beside your furnace.
If the leak shows up during summer while your AC is running, look at the cooling system. The evaporator coil near your furnace produces condensate as it cools your home. A clogged AC drain or overflowing drain pan explains why your AC leaks water near the furnace during cooling season.
A nearby water heater, plumbing line, or water coming down around the flue is another possible source.
Standard-Efficiency Furnace Leaking Water
A standard-efficiency furnace should not normally produce condensate that drains from the furnace.
If water is coming from the metal flue area, turn the furnace off and have the venting inspected. Exhaust should stay hot enough to leave through the flue instead of condensing inside it.
Is It Dangerous? Is the Furnace Ruined?
Water on the floor does not automatically mean your furnace is ruined. What matters is where the water is going.
Turn the furnace off if water is reaching electrical controls, wiring, or other powered components. Shut it down if the leak is actively spreading or you notice a burning or electrical smell.
A wet cabinet or soaked filter needs attention too, but do not start removing electrical panels to look for the source.
If water has reached electrical components, leave the furnace off and schedule online for service.
What You Can Do Now
You can do a few things before we arrive to inspect your furnace:
- If electrical equipment isn’t wet, soak up standing water to keep it from spreading.
- Look for an overflowing drain pan or full condensate pump without taking anything apart.
- Replace a soaked furnace filter.
- Check the area around the furnace for an obvious plumbing or humidifier leak.
Before heating season, use our fall HVAC maintenance checklist to catch drain, filter, and furnace issues before you're running the heat every day.
Furnace Service in the Salt Lake Valley
If you cannot find where the water is coming from, or your furnace has stopped heating along with the leak, Scott Hale Plumbing, Heating & Air will trace the water back to its source. We have served Salt Lake City, Utah County, Murray, and surrounding Salt Lake Valley communities since 1984. Schedule an appointment online or call us today.
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