How Long Should A Home Furnace Last Before It Should Be Replaced?

Most residential furnaces and heaters last between 20 and 30 years. We have been changing out furnaces of this age since I started the company in 1992. Age is, by itself, not a reason to change out your home furnace.

We have worked on repaired furnace more than 100 years old and it is very common for us to work on forced air furnaces that are 40 years old with no real problems whatsoever. Your furnace doesn’t have a “good until stamp” or “best used by stamp”.

Here are some of the reasons that furnaces are changed out or upgraded to new furnaces before their ultimate required time.

  • Water damages to the electronic controls. This happens when the air conditioning system is not maintained and the condensation line stops up. All electronic controls that get wet must be replaced and this can add up to a significant amount.
  • Upgraded air conditioning. Many modern furnaces have variable speed blower assemblies that allow us to regulate the amount of air that blows over the evaporator coil. High efficiency air conditioning systems require more airflow than the common everyday minimum efficiency systems. Older blower assemblies cannot be upgraded to achieve the required efficiency.
  • Noise. Some older furnace become rattle traps that cause the home’s occupants to awaken when the furnace turns on. Older furnaces have on or off modes with the furnace motor coming on near instantly at full speed. Many newer furnaces have a slower ramp up motor which allows a much quieter start up with less cold air blowing into the rooms.
  • Safety. Older furnaces are far more dangerous than newer furnaces. Newer furnaces come with vent safety switches that shut the system down in the event that carbon monoxide starts to spill into the home. Older units do not. Newer furnace have flame roll out switches and fan on controls that prevent flames from leaving the burner chamber and causing fires whereas older furnaces do not.
  • High gas bills and high electric bills. Most of the older furnaces that we change out produce little more than one half (1/2) the rated btus into the home. They are still burning the same number of btus of gas, but ½ of the homeowners gas bill goes up the chimney.

Here are some the reasons that a furnace must be replaced.

  • Ruptured firebox. If the heat exchanger is broken, rusted through, cracked or melted and the furnace is more than 10 years old the heat exchanger will not be stock. It cannot be welded as it will crack right along side of the weld. We cannot fabricated one as it will not meet it’s UL listing. This furnace must be replaced.
  • The electronics controls are no longer manufactured. There were a number of furnaces in the 1970’s and early 1980’s that experimented with integrated circuitry. Many of those circuit boards are out of circulation now and cannot be purchased. Universal circuit boards are a long shot at best and many times installing one leads to more headaches than it solves.
  • The furnace is way too big. Bigger is not better. I have seen furnaces designed for 3000 square foot homes installed in 1100 square foot homes. This, coupled with the wrong size ducting, will burn up a furnace and lead to conditions that can cause fires.

Call Today for Fast, Friendly, On Time, Under Budget Furnace Service 800.261.7971