Along with elements of your air conditioning system, your furnace is likely to be one of the highest value items in your home. Given the high cost of replacement, it can be tempting to keep an old furnace around long past the point where it should be removed. It can also be challenging to know when the time has come to put your old furnace out to pasture. A modern furnace can last for several decades, but you should keep replacement on the table once your furnace is 15–20 years old.
If you think that time might be coming for your furnace, these three questions might help you to decide if a replacement is in your future.
Has Your Furnace Been Well-Maintained?
Keeping a furnace for the long haul requires a significant amount of maintenance. At a minimum, you should have your furnace checked by HVAC services once per year. This inspection will help to ensure that your furnace is running correctly and help you to spot problems before they become too severe. If you've been following this routine schedule, then it's likely that your furnace will easily make it to its second decade. A poorly maintained furnace is more likely to suffer crippling failures, so if you've been neglecting maintenance, then it might be worthwhile to cut your losses once those repair bills start adding up.
Have You Uncovered a Major Issue?
There are a variety of problems that can be showstoppers for a furnace, but a cracked heat exchanger is one of the most severe. If your service technician has uncovered an expensive problem with your furnace, then it's time to evaluate your options carefully. The cost of a heat exchanger repair can be a significant fraction of a new furnace, so it is crucial to consider the likely remaining lifespan of your unit. If your furnace is already more than 15 years old, it may be more cost-effective to install a new unit than to put additional money into your old one.
Are Your Heating Bills Out of Control?
A sudden increase in heating bills usually indicates a problem with your HVAC system. For forced air systems, this can sometimes be the result of issues with your ductwork, but high energy costs can often originate with the furnace itself. If your furnace is particularly old, then it is likely that newer, more energy-efficient models are now readily available. Replacing a perfectly functional furnace to install a more energy-efficient one is not always a cost-effective decision, but it may be a deciding factor when deciding between repair or replacement.
For furnaces that are a decade old or less, repair is almost always the preferable option. If your furnace is older, however, then it is often worthwhile to consider a replacement once repair bills begin to pile up. Combined with the potential for energy savings, replacement is often the cheaper option over the long-run. As with any significant HVAC decision, always discuss your options with an experienced contractor so that you can make an informed decision.