3 Signs Your Furnace Is Running Inefficiently

25 October 2022
 Categories: , Blog


You've noticed an upward creep in your energy bills, and you think your furnace may be to blame. How can you be sure? Sometimes, there are only subtle signs that your furnace is losing energy efficiency, and you need to know what to look for. Keep an eye out for these three signs that indicate your furnace is running inefficiently.

1. Your Furnace is Short Cycling 

Short cycling is a term used when a furnace is starting and stopping more frequently than it should. On average, your furnace should run for 10 to 15 minutes per cycle. If you notice your furnace cycling more frequently than this, it's wasting energy through short cycling.

Furnaces use the most energy at startup when the start capacitor discharges to boost the blower motor. Repeated startups will raise the average power draw of your furnace starkly compared to when it's operating normally. Another unfortunate side effect of short cycling is that your furnace will usually shut off before a comfortable temperature is reached. Your home's comfort doesn't benefit from the extra energy use when your furnace is short cycling.

2. Your Home Has Uneven Temperatures

Have you ever noticed that certain rooms stay chilly even when your furnace is running? This can occur when an underperforming furnace blower is struggling to circulate air through every room in your home. In this situation, the rooms that are furthest from your central furnace assembly will have the most trouble reaching a comfortable temperature. Mechanical wear or poor lubrication in the blower motor could be reducing the total airflow capacity of your furnace.

3. Your Furnace is Outdated

No matter how well you maintain your furnace, it will eventually be outpaced in energy efficiency by newer models. As HVAC technology advances, sometimes the best way of improving your furnace efficiency is simply upgrading to a new one. For example, newer furnaces that use electronic ignition systems no longer consume fuel constantly to maintain a standing pilot light.

The AFUE rating provides a standardized method for comparing energy efficiency between furnace models. Modern furnaces with minimum efficiency typically fall into the 80 - 83% AFUE range. If the AFUE rating on your furnace label is lower than this current minimum, an upgrade could bring valuable monthly energy savings.

Your furnace is one of the biggest sources of energy usage in your home, so it pays to optimize its efficiency. Contact a heating contractor if you notice any of these signs that your furnace is running inefficiently.