On the one hand, modern furnaces are technological marvels. For the most part, they work reliably to send heated air throughout the home in a predictable and efficient manner. 

On the other hand, furnaces are composed of precision-engineered components that will, over time, degrade and start to exhibit symptoms of malfunctioning. Sometimes, these symptoms include less and less heat production. When this happens, it’s not always clear what to do about it. 

Front Range HVAC has extensive experience diagnosing and repairing furnaces of all vintages, shapes, and sizes. With as cold as our winters can get here in Colorado, it’s extra-important to make sure your furnace is operating optimally. And, when it shows signs of failure, the best thing to do is to take action. 

In this blog post, the HVAC professionals at Front Range HVAC are giving you some tips to consider the next time you find yourself dealing with a furnace not heating as it should.

Take These Steps Before Calling for Service 

You shouldn’t have to call for furnace service unless it’s absolutely necessary. In many cases, a furnace that isn’t producing enough heat can be affected by small but important factors—factors you can identify and resolve on your own without having to spend a dime on technical service. 

So, before picking up the phone and contacting the furnace pros at Front Range HVAC, run through this quick checklist. 


  • Check your thermostat. The thermostats of today—especially digital ones—can be the culprit for many HVAC issues. One of the most common problems with thermostats is that their batteries die, or their settings might have changed without your knowing it (the fingers of a curious child can often be to blame).

    To check to see if your thermostat is causing your furnace to not perform as you’d expect, make sure that the batteries powering it are fresh. Also, ensure that the thermostat is set to heat and ‘auto’, and not simply ‘on’.
  • Have you switched from a furnace to a heat pump? Many homeowners are less than impressed with the amount of immediate heat that is produced by a heat pump in comparison with a traditional furnace. If you’ve gone from a furnace to a heat pump, you’ll have to reset your expectations when it comes to how quickly your home is heated by the system.

    While heat pumps can do an exceptional job at saving on energy bills, they are sometimes not as fast to begin sending warm air where it is needed. Give it some time—it’s possible that your new heat pump could just need a little longer to warm things up than the system you switched from.
  • Check the air intake filter. Virtually every furnace manufactured in the past 50 years takes advantage of air filtration technology to screen out airborne particles. If a furnace air filter isfurnace not heating 2 left unchanged for a long enough period of time, it’s possible that the motor powering the air blower can become stressed. This often results in significantly reduced heating.

    To address this, locate your furnaces air filter and inspect it for cleanliness. If it shows signs of being clogged or excessively dirty, replace it with a filter with identical dimensions. Furnace air filters are available at most hardware stores, but if yours isn’t, contact the manufacturer of the furnace to inquire about getting a few spares.
  • Check the gas line. For gas-powered furnaces, a gas supply line is necessary for the overall system to work effectively. Almost all gas supply lines have safety shut-off valves that can be easily knocked closed or otherwise deactivated unknowingly.

    Trace your gas supply line to locate the shut-off valve and ensure that it is open and functioning correctly. Note: if you hear a hissing sound and especially if you detect a rotten egg scent, immediately contact your gas utility and report a possible leak.
  • Inspect air ducts and look for burst seams, holes, corrosion, or frayed sealing tape. Leaky air ducts are notorious for being the cause of furnace heating problems. This is especially the case for leaks that are located nearest to the furnace itself.

    Physically inspect as much of your air ducts as you can, and look for any areas where hot air might be escaping the ducting system. To repair leaks, use metal ducting tape that is specially designed for air duct repair, available at your local hardware store. 


If you’ve gone through this checklist and haven’t been able to detect any issues, and if your furnace is still exhibiting symptoms of low heat, then it’s probably a good time to call in the experts. 

Thankfully, the team at Front Range HVAC is expertly trained and capable of running a battery of tests on your furnace to determine what the problem is. For most furnaces, we can arrive at a root cause within just an hour or two. Once we know what is causing the furnace to malfunction, we can order the necessary replacement parts, perform the repair, and get you back to enjoying a toasty warm living space. 

In the event that your furnace is too far gone to be repaired, we can provide you with a wide range of furnace replacement options. We’ll even remove the old furnace for you and dispose of it in an environmentally friendly way.

To schedule a furnace inspection, contact us today or call (303) 872-9060.