Seeing a water leak coming from your Vancouver, BC, home’s furnace can feel shocking. While this could indicate a serious problem with your furnace, several relatively minor issues can also cause your furnace to leak water while the air conditioner is on. The following are 11 reasons your furnace could leak water when the air conditioner is on.

1. Refrigerant Levels Are Low

Symptoms of an AC unit with low refrigerant levels include a unit that does not cool as it should and the appearance of water leaks. The evaporator coils in an air conditioner that does not have sufficient refrigerant might freeze over. When they thaw, they overflow into the drain pan. This can lead to water puddling around your furnace.

2. It’s Time to Clean the AC Filter

A dirty AC filter inhibits adequate airflow. This causes evaporator coils to freeze. When they thaw, they can overflow into the drain pan, leading to water leaks. If changing the air filter does not correct the problem, additional repairs and maintenance may be required.

3. It’s Too Cold For Air Conditioning

Most air conditioners operate the best when outdoor temperatures are over 60°F. Using an AC when temperatures are lower than this point can lead to frozen evaporator coils. When they thaw, pieces of ice can block the drain pan opening. The drain pan will overflow, and a leak could happen.

4. Damaged Condensate Pump

Your HVAC system might have a condensate pump to help drain accumulating water. This is usually true if the drain system sits above the AC unit. Water can collect in the pan and leak out if the condensate pump is damaged or broken. You can visually inspect the pump to make sure it has power going to it. If it has electricity but is not functioning, the damaged condensate pump may need to be repaired or replaced by HVAC professionals.

5. A Blocked Condensate Drain

Warm summer air creates condensation on a cool evaporator coil. This water drains into the drip pan that is inside your furnace. When everything works as it should, condensation exits the drip pan via the drain piping.

Minerals, mold, debris, and other materials can block the drain with time. This prevents water from draining correctly.

Many air conditioning units have a safety device that automatically switches off the AC when the drain is blocked. This protects your home from water damage. If you notice a leak near your furnace while the AC is on and your AC unit is unexpectedly turning off, a blocked condensate drain could be the culprit.

6. A Disconnected Drain Line

This does not happen frequently, but it is possible for the piping that is connected to the drain pan to become disconnected or to get loose. This could happen if someone attempts DIY repairs or maintenance on their unit. You may be able to visually inspect the drain line to ensure that is connected to the coil pan. If it’s not connected, the HVAC professionals at Western Pacific Heating, Cooling & Airflow can help you resolve the issue.

7. High Humidity Combined With Poorly Insulated Ductwork

If air ducts are not properly insulated, warm air could interact with the cold surfaces of your air ducts, creating condensation that works its way back to the furnace area. This problem is especially pronounced if the ductwork that passes through your attic is poorly insulated.

Couple this with summers that have extremely high humidity, and the chances of condensation buildup resulting in leaks around the furnace increase. Homes with a leaky roof or that lack proper ventilation are at a higher risk for increased humidity-related air conditioning leaks.

8. The Evaporator Coil Could Be Dirty or Cracked

If your unit’s evaporator coil is dirty or cracked, you might see drips of water around or outside your furnace. This is caused by water bouncing off the evaporator coil instead of draining from the condensate line into the drip pan. Holes in the insulation around your unit’s evaporator coil might redirect the water, causing it to drip. Regular maintenance is key to maintaining the evaporator coil and preventing this type of leakage.

9. Condensate Pan Needs to Be Replaced

If your air conditioning unit is between 12 and 15 years old, some of its parts, including the condensate pan, may be nearing the end of their life cycle. HVAC professionals can inspect the condensate pan for signs of rust or decay. In many cases, replacing the pan remedies the leakage issues.

10. Inadequate AC Installation

If your newly installed air conditioning unit is dripping water, this can be an issue with improper installation. For example, if the AC drainpipes are too small, they could impede the water flow from the drain pan. The result is a unit that leaks water.

If your central AC is not installed level, it can lead to water spilling or leaking. If you have a new unit installed, it’s important to ensure that the work is done by trained, experienced, and licensed professionals.

11. The Thermostat Is Set Too Low

The AC can leak water when a thermostat is set too low compared to the outside temperature. Running the unit at extremely cold temperatures for long periods can cause ice to build up on the evaporator coils. A hole can form in the drain pan, leading to condensation overflow and leakage.

Why Does My Air Conditioner Collect Water in the First Place?

Your HVAC system is designed to affect your home’s temperature and humidity levels. As the warm air from your home blows over the cold evaporator coils, the water in the air condenses, removing humidity. Lower humidity levels make the air inside your home feel cooler. The humidity that is removed from the air is then collected into the drain pan.

Can You Use Your Air Conditioner When It Is Leaking Water?

Your AC unit will most likely continue to function despite leaking water. However, it will likely not work as efficiently as it did before the leak. Until the reason for the leak is identified, it’s preferred that you power off the unit until you can have the issue addressed.

In many cases, the damage that caused the leak will only get worse if your unit keeps running. You can experience compressor failure and other serious issues. Additionally, an indoor AC leak could potentially damage your walls, ceiling, and furniture. With time, this could lead to mold growth. When you notice a leak, your best bet is to contact HVAC technicians and have them help you fix the issue before it gets worse.

Work With the Top Heating and Cooling Services in Vancouver

At Western Pacific Heating, Cooling & Airflow, we are experts at providing HVAC services to residential, industrial, and commercial clients. We help our clients get control over the comfort of their property while refreshing and energizing the air they breathe. We are proud of our work and strive to exceed our customers’ expectations every step of the way.

Our services include residential HVAC installation, repair, and maintenance. We install residential heat pumps, air purification systems, and water heaters. We do commercial HVAC and air balancing. Contact Western Pacific Heating, Cooling & Airflow today to work with experienced professionals who care about quality and getting the job done right.

Western Pacific Heating, Cooling & Airflow

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