How Long Does a Furnace Last in the Phoenix Area?

The short answer? Most furnaces last 15–20 years in the Phoenix area.

The long answer? The lifespan of your furnace will depend on:

• Whether your furnace is properly sized
• The AFUE rating of your system
• How well you maintain it

We’ll go over how each of the factors above impact how long your furnace will last.

Why this matters: A furnace that’s properly sized for your home will last much longer than one that’s improperly sized.

We’ll explain.

If you have an oversized furnace, your furnace will likely turn on and then shut off quickly. This problem, called “short cycling”, happens because the furnace heats your home too quickly.

While this might not sound like a problem, short cycling puts excess wear and tear on your system.

See, your furnace is designed to run slow and steady. So, when it starts and stops more frequently than it should, parts on the furnace wear out quicker than normal—increasing repairs and shortening the lifespan of your furnace.

And an undersized furnace will run non-stop trying (and failing) to keep up with the heating demands of your home, which will also results in frequent repairs and a shortened lifespan.

Signs of an undersized furnace:

• Your furnace runs constantly
• High energy bills
• Your home never feels warm

Signs of an oversized furnace:

• Your furnace turns on and shuts off quickly
• High energy bills
• Some rooms feel warmer than others

Think you might have the wrong size furnace? Contact a professional to perform a heat load calculation on your home.

Why this matters: Furnaces with higher AFUE ratings will last longer because they come with features that put less wear and tear on the system—helping it last longer.

AFUE (Annual Fuel Utilization Efficiency) is a measurement of how efficiently your furnace uses fuel. The higher the AFUE rating, the more efficient the unit.

High-efficiency furnaces usually have AFUE ratings between 90% and 98%.

To make your system run more efficiently, high-efficiency furnaces typically come with advanced features that ultimately increase the furnace lifespan.

Some of these advanced features include:

• Variable-speed blower motor. Standard furnaces come with 1 or 2 pre-set blower motor speeds (HIGH and LOW). Variable-speed units can essentially operate at any speed, based on how much heating your home needs.
• Modulating burners. Standard furnaces come with 1 pre-set burner mode: HIGH. Modulating burners can control how hot the burners get, allowing for more precise temperatures.

Why this matters: A furnace that’s been regularly maintained over the years will last longer than one that hasn’t.

Your furnace isn’t a “set it and forget it” kind of system. Over time (as your system runs), parts on your furnace get dirty and misaligned, making them operate less efficiently than normal.

A furnace check-up or tune-up will essentially recalibrate your system, making sure all the parts are clean and work properly.

Even in Phoenix, where your furnace probably doesn’t see a lot of action, regular furnace maintenance will help:

• Prevent furnace breakdowns, since your HVAC Service Technician can catch minor issues before they turn into expensive repairs, extending the lifespan of your system.
• Keep your energy costs down, since parts of your furnace will be cleaned, helping your system run more efficiently.

How often does your furnace need to be serviced, you ask?

Well, ENERGY STAR recommends getting your furnace serviced on an annual basis, preferably before the heating season begins.