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Why Is My Furnace Leaking Water?

waterIf you’re asking this question, you’re probably a bit confused. After all, furnaces don’t use water to run, do they? A boiler uses water, but a furnace heats up air with either gas burners or electric heating elements, and then sends the air into the ducts.

And yet, there is it: water leaking out of the furnace cabinet onto the floor. What’s happening? And does it mean you need heating repair in Chapel Hill, NC for your HVAC system?

We’ll take a closer look into this apparently odd, but actually common, heating problem.

High Efficiency Furnace Condensation

Although a furnace doesn’t use water to run, special high efficiency furnace produces condensation during combustion. This is because a high-efficiency furnace collects vapor in the heat exchanger from the cooled-off combustion gas rather than venting the gases out a flue. This vapor moves to a second heat exchanger, were it’s condensed to release further heat. It’s this second combustion chamber that allows high-efficiency furnaces can produce more heat energy from their fuel. The furnace then vents the vapor out of the system.

If there are clogs in the condensation tubing, or breaks in the tubing, it can lead to the condensation escaping onto the floor. You’ll want this repaired as soon as possible. Another possibility is a faulty second heat exchanger. Damage to the heat exchanger is usually serious enough to warrant having the furnace replaced.

Poor Venting in a Mid-Efficiency Furnace

A mid-efficiency furnace (lower than 90% AFUE) shouldn’t develop condensation because the vapor from the heat exchanger is vented out directly through a metal flue pipe. (High-efficiency furnaces use PVC pipes for flues.) However, this flue pipe must be correctly sized, or else the vapor will start to cool down in the pipe and create condensation that then leaks down out of the furnace. Poor venting is a major problem that needs to be addressed right away. (If you always arrange for furnace installation with licensed professionals, you shouldn’t run into this issue.)

The Air Conditioner Is at Fault

The standard HVAC configuration in homes is a combination of a furnace and air conditioner in a single cabinet, where they share the same blower fan. The air conditioner is housed over the furnace. If the air conditioner has a clogged condensate drain, water from the condensate pan will start to overflow and spill out into the cabinet. It may look like the furnace is leaking, but it’s actually the air conditioner.

This is still something that needs professional repair ASAP. Water dripping onto the furnace can create corrosion, and corrosion puts the furnace in danger of cracks along the heat exchanger, a potentially hazardous condition. You also want this fixed so the AC can work correctly.

Remember, no matter what is causing water leaks from the HVAC cabinet, water damage is expensive to remediate and can create mold and mildew growth. You never want any leaks from your HVAC system! Let our expert technicians track down the source of the leak and have it fixed or help you arrange for a system replacement if the damage is bad enough.

Call on Bud Matthews Services for all your home services needs in Durham, NC.

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