During the NYC winters, we need our furnaces running efficiently and constantly.  Coming home to any problem with your furnace during wintertime is never ideal, but when it comes to a leaky furnace, there are a few key troubleshooting steps you can check before calling professional help.

Conventional or Condensing Furnace?

When it’s the winter and you’re having furnace leaking issues, the first thing you want to check is whether you have a conventional furnace or a condensing furnace.  You can most likely tell if your furnace is conventional if it has a metal exhaust pipe, or if it’s Annual Fuel Utilization (AFUE) rating is below 90 or is not listed at all.  Likewise, you can most likely tell if your furnace is condensing if it has a PVC exhaust pipe and has an AFUE rating higher than 90.  If you have a conventional furnace, it should never be producing water, regardless if it’s the Winter, so if it is, we highly recommend you call an HVAC professional to come to inspect it immediately.

Common Causes for a Leaking Furnace in the Winter

  • Flue pipe: A flue pipe that isn’t fitted correctly can often be the cause of a leak.  As stated above, condensation can be a byproduct of heat production from your heat exchanger.  If this pipe that drains the condensation is not fitted properly, it is easy for the water to leak out of the pipe and onto your floor.  This is the first place we suggest you look, especially with a conventional furnace. Conventional furnaces are not supposed to produce condensation within the unit, but rather use the drainpipe to push gases outside where they then condense.  If the drainpipe is not fitted correctly, the gases can condense within the pipe, causing a leak.
  • Humidifier: While AC units have a dehumidifier, furnaces have a humidifier. This adds moisture to the air as it is heating which allows more heat to be trapped and therefore heats your house more efficiently.  You can often tell if your furnace has a humidifier if it has a box attached to it with several pipes and wires going toward your furnace.  A common reason why your humidifier is causing your furnace to leak is simply that the filter is clogged, in which case you simply will need to change the filter.  Another possible issue is if the drain is clogged, in which case it will need to be cleaned.  Leaks, especially on the interior of a furnace, can often cause severe damage to it.  If you do not know how long it has been leaking or cannot resolve the issue, it is best to contact a professional.
  • Secondary Heat Exchanger: A secondary heat exchanger absorbs combustion exhaust from the primary heat exchanger and releases this excess heat, which can cause water vapor to be produced.  If there is damage to your secondary heat exchanger, this can often be a sign that your furnace has reached or is close to reaching the end of its life as they are very costly to repair. If this is the case, it is often more cost-efficient to replace the furnace.  Some ways you can check to see if it is cracked is if it there is water dripping down the fan compartment. Another way to check it is by looking at the secondary heat exchanger to scan for any visible cracks or corrosion.  If you believe the secondary heat exchanger is likely the culprit and you are not confident in your handyman skills, we recommend calling a professional to conduct an inspection.
  • Condensate Pump: An issue with the condensate pump is exclusive to condensing furnaces. Some of these furnaces have what is called a condensate pump which is used to push the condensation created within the unit out to the pipe.  If the pump malfunctions, water can back up and cause a leak from your furnace.  In this case, you will need to call a professional out to replace it.

Still Need Help with Your Leaking Furnace in the Winter?  Call Figlia & Sons!

If you find your furnace leaking in the Winter and need professional HVAC help in the NYC area, look no further than the experts at Figlia & Sons.  With over 50 years of experience (and 50 Winters) in the HVAC installation, PTAC repair, and replacement of HVAC equipment in NYC, our highly skilled technicians will provide fast and reliable service to your furnace. Call us today at 212-686-0094 to speak with a knowledgeable representative from our team or fill out our contact form!

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