If your home gets heated by a furnace, odds are you’ve noticed some water leaking out of the unit itself — and it’s not just from the drain. You may be seeing water on the floor or puddles around your baseboards where pipes come into your house. If you’ve turned up the thermostat and nothing happens, this is likely because your furnace is leaking. This blog will go over some common causes of furnace leaks.

1. The Drain Is Blocked

The first thing to check when your furnace starts leaking is the drain line that you can easily access outside your house. If this line is clogged, your unit could be filling up with water instead of blowing warm air into your home. This could also be why you’re not feeling any heat. If too much water gets in, it can cause problems within the system.

If the drain line is blocked, you may be able to fix it yourself with a plunger.  However, if this doesn’t work, you may need to contact a professional plumber. Depending on how far your drain line extends outside of your home and how much ice and snow there is in the winter, your unit may fill up more than usual in the winter — especially if you live in an area that gets lots of snow and ice.

2. The Expansion Tank Is Leaking

Another way your furnace can start leaking is if the expansion tank on the back of your unit has sprung a leak. The purpose of this device, which has clear tubing coming out of it, is to keep up with coolant expansion and contraction during use. When the coolant heats up, it expands, so the tank allows for this expansion. When the coolant cools down, it contracts back to average temperature; then, you can heat or cool your home again.

If your expansion tank is leaking, then your coolant is not being sealed correctly. This means that you could end up with a bunch of coolant on the floor or a messy, wet basement. Turn off the gas to your furnace and call an HVAC professional immediately if you notice this happening.

3. A Furnace Cabinet Is Blowing

This is another problem that you can check yourself, but it may require the help of an HVAC professional. The primary function of your furnace cabinet is to keep warm air in and cold air out, so if they’re not sealed properly, they could let cold air in. A damp basement or floor could be the result. Try to rock the doors back and forth to make sure they’re properly sealed.

4. A Thermostat Is Blowing

Your furnace thermostat may be broken if it’s not regulating the temperature correctly. This could be one of two problems: One, there may be too much dirt or rust inside the switch, which would prevent the unit from turning on at all. Second, there may not be enough air getting to the switch. This means that it’s going to turn on even when your thermostat says otherwise. To ensure this is not happening, make sure you have a clean filter on your air filter and good airflow in the whole system.

5. Air Filters Are Clogged

Another reason your furnace may be leaking is due to clogged air filters. The device needs proper airflow to work at its best, so if you have a dirty filter, it may be triggering the unit to turn on when it shouldn’t. Air filters are relatively cheap and easy to replace, so most homeowners can quickly fix this.

6. A Coolant Filter Is Clogged

If you have a coolant filter on your unit, then replacing this filter could prevent furnace leaks. If it’s too dirty, the coolant may not be able to circulate properly through your system. A clogged cooler can reduce the efficiency of your unit and make it too hot or too cold in some areas of your home. If you notice inconsistent temperatures or suffer from a leaky furnace, consider changing out this filter.

7. The Thermostat Is Broken

If you’ve tried several heating tools before calling an HVAC professional, it could be your thermostat that’s the problem. This is bad news if it’s your primary heating tool; with no thermostat, you’ll be at the mercy of the system. If you have a secondary heating device or fireplace, this is good news.

8. The Fan Motor Is Broken

If your fan motor is broken, it can cause leaks in your system. This means that coolant may go into places it shouldn’t go, leading to leaks or other problems in the future. It’s essential to keep track of these motors to ensure they don’t break down when you rely on them the most.

9. The Blower Motor Is Broken

If your blower motor is broken, it can cause an excessive amount of heat in some areas of your house while letting cold air circulate in others. If you notice that the unit is blowing cold air instead of warm, this could cause your leak.

10. A Baffle Board Is Blowing

A baffle board can cause leaks if it’s forever blowing cold air on one side. If you notice that only part of your house is getting heat, this may be the problem.

11. A Damaged Cooling Coil

This can cause cooling issues, too. A damaged coil can leave coolant running through unused ductwork or other system parts; it could also get clogged up by dust and dirt. The result is a leaky system. If you have a coolant filter on your unit, it may be clogged with dust or dirt, so it’s essential to change this filter regularly.

12. The Evaporator Coil Is Broken

This part of your unit can leak due to age or improper installation. A broken evaporator coil can cause the system to be too hot or too cold in certain areas of your home. If you notice the furnace cycling on and off — meaning it turns on and off — this may be because of a broken evaporator coil.

13. Improper Installation

A lot of your furnace problems may have to do with improper installation. If your unit was not properly leveled, you could leak into your system. If it was installed on the wrong kind of foundation, you could be at risk for leaky furnaces as well. It’s essential to check with an HVAC professional to ensure your unit is installed correctly before calling them out for a repair job. For furnace installation in Jamesville or Syracuse, NY, contact Holbrook Heating & Air Conditioning. We offer all kinds of heating and cooling services, including new installation, repairs, and system maintenance.

Leaky furnaces can be frustrating to deal with, mainly when they cause mold and other issues in your home. If you notice that your furnace is leaking, our technicians can help. We can spot potential problems in your system and ensure you’re getting the proper air circulation you need to stay cool in your home. No matter why your furnace is leaking, we can find the cause and repair it. For heating and cooling services, water heater installation and repair, and ductless cleaning, contact Holbrook Heating & Air Conditioning in Syracuse today.