Furnace Date Codes: What They Mean, and When You Need to Act

If you own a gas or electric furnace, it’s important to know when it was manufactured. The production date is typically found on the serial number on the side of the unit or through an inspection plate. Knowing this information can help you avoid upcoming service requirements and cut costs down the road. If your furnace was built before 1993, then it isn’t required to have a date code. If you find that your unit does have a date code, then you need to know what it means and how it can help you. A furnace date code indicates when it was built and if there are any upcoming maintenance requirements for that unit. Understanding these four types of codes will help you understand exactly what that sticker means and when to take action with your gas or electric furnace:

What Does the Date Code Mean?

The date code is an eight-digit number with a letter prefix, which is the month and year of the manufacturer. The numbers are broken down into two sections: The first two digits indicate the week the furnace was built and the last six digits indicate the year. For example, a code of 1125 indicates that it was built in the 12th week of 2017. The letter at the beginning of the code refers to the plant where the furnace was built: The letters in the date code don’t seem to match up correctly with a specific month or season. The dates are based on the Julian calendar, which is a solar calendar that is 13 days behind the Gregorian calendar. Because of this, the letter at the beginning of the date code will change every four years.

Check Your Furnace’s Oil and Filter

Before you even turn on your furnace, you should make sure that your fuel oil is clean and that you have a new filter in place. Your furnace’s filter will become clogged and reduce airflow over time, which can cause your furnace to work harder and increase energy use. You should also check the furnace’s oil level. Minimum levels will be specified in your furnace’s manual, but it’s generally recommended to change the oil every two years. If you don’t change the oil in your furnace, the unit will need to be replaced sooner. If you notice that your furnace’s filter is extremely dirty, it may be time to clean the filter. Cleaning a furnace filter may seem easy, but it isn’t something that should be taken lightly. Improper cleaning can cause a fire in your home.

When You Need to Change Your Filters

There is no hard and fast rule for when you should replace your furnace filter. Some experts say to replace it every month, others say every 3 months, and still, others say that you should replace the filter every 6 months. No one rule will apply to everyone, because every home will have different conditions that will cause the filter to clog more quickly. If you have pets in the home, then you will need to change your filter much more often. If you have allergies, then you may want to change the filter more often as well. One thing that you should always do, though, is to make sure that the furnace filter is sized correctly for your furnace. If the filter is too small for your furnace, then it will clog up much more quickly and have to be changed more often. If the filter is too big, then it will take longer to clog up and will have to be changed less often.

When You Need to Change Your Thermostat

If you have a programmable thermostat, then you should check its date. If it was manufactured before 2005, then it will need to be replaced with new control. If the thermostat is more than 10 years old, then it may not be compatible with new furnace technology. If your furnace was manufactured in 2005 or later, then it may need a modern communicating thermostat. Newer furnaces will have the communicating capability, and if your thermostat doesn’t have that capability, then it won’t work with your furnace. If your furnace is older than 10 years, then you may want to consider replacing the thermostat with a communicating model. If your furnace was manufactured before 2005, then you want to replace the thermostat. If the thermostat isn’t communicating with your furnace, then the furnace will run longer than necessary.

When You Need to Change Your Condenser and Dampers

If your furnace was manufactured before 1995, then you should consider replacing the condenser and dampers. After 1995, it was required for the manufacturer to use a corrosion-resistant material for the heating element. If your furnace is older than 20 years, then you should replace the condenser and dampers. If your furnace is less than 15 years, then you should consider replacing the condenser and dampers. If your furnace was manufactured before 1995, then you should probably replace the condenser and dampers. If your furnace is less than 15 years old, then you may be able to extend the life of your furnace by replacing the condenser and dampers.

Bottom line

A furnace date code will tell you when it was manufactured. Understanding what that date means can help you avoid upcoming service requirements and extend the life of your furnace. Before you even turn on your furnace for the season, it’s important to check the oil, filters, and other components. By doing things like changing your filters regularly, you can help your furnace run better and save you money.