When a home is new, everything works right. If there is a glitch, it’s almost always due to a bad part and replaced immediately with all the warranties provided and covering the first year of living in the new residence. However, as time goes on, wear and tear kicks in, and people begin to start customizing the home for their own needs and wants. However, the air and heating systems stay solid, and both continue to stay reliable until at least a decade into owning a home. However, at about year 10 and afterwards, wear and tear starts to add up. Maintenance can help prolong the life of a furnace, keeping it tuned, clear of contaminants, checked and evaluated for performance, and clear of leaks or repair needs. Even a top-running furnace gets old at some point and starts to struggle. The question of replacement starts to come up.

Signs of a Furnace Failure

Two big signs start to signal a furnace in trouble. The first is weak airflow. Heat doesn’t move around a home on its own. It needs a blowing force and a circuit by which to be distributed. This is typically through ductwork, but the blowing force is what propels the air and moves it from room to room from the furnace. So when that air flow pressure dies off or weakens noticeably, it either means the furnace is not generating sufficient heat to warm the house, or the heater blower engine is starting to suffer.

If the cause is the blower, it can be isolated and separated from the furnace and replaced. However, a homeowner needs to keep in mind the cost/benefit aspect of doing a partial replacement. First off, the furnace is still the old one and may fail eventually in a few years as well. Adding a full-strength blower to it may actually speed up the eventual failure versus help the situation, putting a full-strength pull pressure on the furnace. Alternatively, it may keep going, adding another five years of life, roughly speaking, but eventually the furnace will go. Then, the rest of the system will need replacement. Most service teams recommend a complete changeout, so the entire system matches. Yet, a partial repair can be a lower cost in the moment, especially if one has a limited budget.

Noises from the furnace, particularly irregular ones can be signs of aging. When operating, louder sounds tend to be adjustments due to temperature changes, but there can also be signs of weaknesses starting in the furnace assembly as well. Newer systems in good shape are able to handles these stresses as they heat up and cool down, but older systems are strained, and the noise becomes louder as the assembly struggles with integrity. Once these signs start to happen regularly with each heating, a technician can evaluate the furnace and estimate what it’s likely lifespan is that is remaining. At best, after a decade, it’s as much as 20 years in very good condition and 5 years in rough, less maintained status.

The Decision

Making the decision to repair or replace furnace systems is a tough one that every homeowner faces if they stay present in the home long enough. It involves a big commitment that should be associated with planning to stay in the home. If not, then it makes more sense to repair the furnace to last a few more years past the same, which then makes the question a commitment for the next owner. 

Whichever choice is made, a step forward is sooner or later essential as the current furnace begins to stumble. And the longer one waits, the closer it gets to shut down. So, the decision can't be avoided; it's best for a homeowner to anticipate the fork in the road and then make the decision that's best for the circumstances.