9 Signs Your Furnace is Going Out

We all know it’s important to be prepared. Regarding your furnace or other heating system, it is no different. It’s best to give your furnace the attention it needs before an emergency. Watch for the signs your furnace is going bad so you know when to call.  

Although we do offer emergency heating system repair 24/7/365 in Central Maryland, we would much rather help you avoid the stress and pressure by being prepared. If you notice these signs that your furnace is going bad at home, let’s chat about your furnace replacement options!

Signs Your Furnace is Going Out

Most of these warning signs apply to a gas furnace, however, many of these signs can be applied to other heating systems like geothermal systems, mini-split, heat pumps, etc. Here is how to tell if your gas furnace is reaching the end of its road:

  1. Increasing illnesses
  2. High furnace age
  3. High and unexplained utility bills
  4. Sudden troublesome noises
  5. Pilot flame color
  6. Dry air
  7. Soot
  8. Frequent repairs
  9. Poor temperature control.

Increasing illness symptoms

More instances of flu-like or cold symptoms among family members may be due to a carbon monoxide leak in the gas heater or poor ventilation of the exhaust. When carbon monoxide builds up in the home, it affects us and can make us sick in small doses. In higher concentrations, exposure is deadly.  

Of course, the most important thing here is your safety and health, not your furnace. A carbon monoxide detector is a real help for your home, business or commercial property, as it’s the only way to detect carbon monoxide leaks.  

After the fresh air and safety concerns are taken care of, we can certainly help with your HVAC system.  The carbon monoxide can come from different sources of the furnace. If the exhaust is not properly controlled and vented out of the living space, the harmful gas builds up. Another source of the carbon monoxide coming into the living space is commonly a cracked heat exchanger or other cracked parts of a furnace. This typically happens in older systems.  

High furnace age

We know the saying “nothing lasts forever” and this also applies to furnaces and other heating systems.  Unfortunately, as furnaces age they begin to fail. The good news is that you can see the signs the furnace is going bad and be prepared or even avoid it completely. Hardly any of us know the age of our furnace however, we do have a “feel” that a furnace is “really old.” 

Check the age of your heating system by looking at the information on the label attached directly to the unit. If you have any questions, ask us during our twice-yearly maintenance or search online. Many manufacturers have posted their manuals online.  

The average age of a furnace is 15-20 years, however some models last longer with proper maintenance. Other types of HVAC equipment have a service life longer or shorter than the furnace average. The issue with heating systems lasting longer is that at 20 years, often the efficiency of the HVAC system is diminished even if the system still works. This causes higher energy bills.

High heating bills without explanation

As a furnace ages, it loses efficiency and your heating bills increase as the heating system runs more frequently. This uses more fuel, however it does not always mean more productive heat. The heater runs and runs but doesn’t keep the space comfortable.  This is one of the signs your furnace is going bad.

A tune up may help in this case and also helps save money. Although, there is only so much to recoup with an older system, we are happy to help extend the life of your existing HVAC system and to help you make an informed decision on when it may be time for a replacement. Either way, we are glad to work with you to find the best success for your needs. We help you to weigh the signs that the furnace is going bad to make a financially sound decision.

Strange noises

Noises are often signs that the furnace is going bad. In some cases they are frustrating and stressful but when caught early, many of these issues are simply fixed. Fixing a young or mid-aged heating system makes a lot of sense and can save money.  

We’ve been locally owned and operated in the Central Maryland area for decades and we know that if we do the best for your needs with open and honest communication it will help you and us in the long run. We bring our family values to every HVAC service. We’re here for the long run. So if you hear a squeal, a new click, grinding, or popping when your furnace is at any point in the heating cycle, it’s best to have a tech take a look and catch things early.

Pilot flame color changes

A gas furnace should have a vibrant or bright blue flame. When you see a weak and wavy or flickering flame, this indicates gas is not being completely burned. Pilot light color changes are another indicator that carbon monoxide is not venting away from the system safely.

A yellow flame is a clear sign that the gas is not burning properly. Dirty or partially blocked systems can produce this. It’s also another sign that a call to your trusted HVAC contractor is needed to save money and keep you a bit safer.

Dry air

A dry environment can be caused from issues with the humidity control, but also can come from an undersized system which is running too frequently, or an oversized unit which does not run long enough. Replacement is the only way to get the correct size furnace your home needs.


Soot is generated from “day one” if the system is improperly installed, however it also can be from an aging system that may need to be replaced.  Soot is one of the signs your furnace is going bad.

Poor temperature control

If your thermostat is no longer working properly, it may need to be replaced. There are a lot of “cool” new features that many thermostats offer that help to keep you more comfortable and save money. When some rooms are hot and others are cold, this is a sign of a needed repair. Though, many times this has other root causes like a poorly engineered system, poor thermostat location, or poor insulation.  

More frequent repairs

When repairs are happening more frequently it is a good sign that it may save time and money to add a new, more efficient HVAC heating system in Central Maryland. Increased spending on repairs is a serious sign your furnace is going bad.

Don’t Ignore the Signs Your Furnace Is Going Bad – Call Now!

The signs your furnace is going bad means it’s time to replace. Trust Grove Heating and Cooling to guide you in the right direction! If you would like to schedule a furnace replacement or speak with a trusted, award-winning, local HVAC company with family values, decades of experience and industry connections, give us a call. Remember to ask about our great rebates, lifetime workmanship, specific materials and equipment warranties.

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