When temperatures start dropping in Johnson County, Kansas, your furnace suddenly becomes one of the most important pieces of equipment in your home. 

Most homeowners don't think much about their heating system until something doesn't seem right. Maybe the furnace starts turning on and off more often than usual. Maybe you notice a strange smell when it starts. Perhaps one room stays colder than the others, or your heating bill suddenly seems much higher. 

Some furnace symptoms are fairly normal. Others can indicate a problem that should be checked before you continue running the system. 

At One Hour Heating & Air Conditioning of Johnson County, we've been helping homeowners in Olathe and throughout Johnson County, Kansas, with heating and cooling systems since 1987. Here are some of the most important things we think local homeowners should know about their furnaces. 

Carbon Monoxide and Your Furnace: What Homeowners Need to Know

If your home has a gas-burning furnace, carbon monoxide safety should always be taken seriously. 

Carbon monoxide, commonly called CO, is especially dangerous because you cannot see it, smell it or taste it. 

A properly operating and properly vented furnace should safely carry combustion gases out of your home. However, problems involving combustion, venting or other components of a fuel-burning heating system can potentially create a carbon monoxide hazard. 

What are the symptoms of carbon monoxide exposure?

Possible symptoms can include: 

  • Headache 
  • Dizziness 
  • Weakness or unusual fatigue 
  • Nausea or vomiting 
  • Chest pain 
  • Confusion 
  • Loss of consciousness in severe cases 

Because several of these symptoms can feel similar to the flu, carbon monoxide exposure isn't always immediately obvious. 

Where should carbon monoxide detectors be installed?

Homes with fuel-burning appliances should have functioning carbon monoxide alarms. The U.S. Consumer Product Safety Commission recommends CO alarms on every level of the home and outside sleeping areas. CPSC also recommends testing CO alarms every month and replacing batteries or the alarm itself according to the manufacturer's instructions. 

What should I do if my carbon monoxide alarm goes off?

Treat a CO alarm seriously. 

Get everyone outside into fresh air immediately and call 911. Don't stay inside trying to determine whether the furnace is the problem. CPSC advises homeowners not to ignore a sounding CO alarm and to get outside immediately before calling 911. See CPSC's current carbon monoxide safety guidance. 

If the furnace or another fuel-burning appliance is determined to be the source, don't operate that equipment again until it has been inspected and the problem corrected by a qualified professional. 

Why Does My Furnace Keep Turning On and Off?

A furnace naturally cycles on and off as it maintains the temperature in your home. 

But if it starts turning on, running briefly and shutting back off repeatedly, you may be experiencing what's commonly called short cycling. 

There are several possible reasons a furnace may short cycle. 

Sometimes the issue can be relatively simple, such as restricted airflow caused by a dirty filter. Other possibilities include thermostat problems, overheating, airflow restrictions, safety controls, flame-sensing problems or other furnace components that aren't operating correctly. 

Equipment sizing can also affect cycling. A furnace that is significantly oversized for the home may heat the space very quickly and shut down, only to restart again a short time later. 

Is furnace short cycling bad?

Occasional cycling isn't automatically a problem. 

But frequent short cycling shouldn't simply be ignored. 

Repeatedly starting and stopping can increase wear on furnace components, reduce comfort and potentially increase operating costs. If your furnace suddenly begins cycling much differently than it normally does, it's worth having the cause investigated. 

Is a Burning Smell From My Furnace Normal?

Sometimes. 

When you turn on your furnace for the first time after months of not using it, accumulated dust inside the heating system can create a temporary dusty or slightly burning smell. 

That smell should normally begin disappearing as the furnace operates. 

But not every burning smell should be dismissed as "just the furnace warming up." 

Furnace smells that deserve attention

Turn the system off and have it evaluated if you notice: 

  • A persistent electrical or burning-plastic smell 
  • Smoke coming from the furnace or vents 
  • An unusually strong odor that doesn't go away 
  • An overheating smell that appears repeatedly 
  • A gas odor 
  • A smell accompanied by unusual noises or system shutdowns 

If you suspect a gas leak, leave the home and contact the appropriate emergency or utility service rather than trying to diagnose the furnace yourself. 

When it comes to unusual furnace odors, it's much better to investigate something that turns out to be minor than ignore a potential safety problem. 

What Furnace Noises Should Homeowners Pay Attention To?

Furnaces aren't silent. You'll normally hear burners ignite, the blower start, air moving through the ductwork and the system shutting down. 

What deserves attention is a new noise or a significant change in the way your furnace sounds. 

Examples include: 

  • Banging or booming 
  • Grinding 
  • Screeching or squealing 
  • Persistent rattling 
  • Buzzing or electrical sounds 
  • Repeated clicking without the furnace starting 
  • Unusually loud airflow 

Different noises can come from different components, so sound alone usually isn't enough to diagnose the problem. But if your furnace suddenly sounds noticeably different, that's a good reason to have someone take a look. 

Why Are Some Rooms Hot While Others Stay Cold?

Uneven temperatures don't necessarily mean your furnace is failing. 

The problem could involve: 

  • Dirty or restrictive filters 
  • Closed or obstructed supply registers 
  • Ductwork problems 
  • Airflow balancing 
  • Thermostat location 
  • Insulation or air leakage 
  • Blower performance 
  • The size or design of the HVAC system 

If one room has always been difficult to heat, the issue may involve the home or duct system rather than the furnace itself. 

But when a home that previously heated evenly suddenly develops hot and cold areas, something has changed. That's worth investigating. 

Why Is My Furnace Running but Not Blowing Much Air?

Weak airflow is another symptom homeowners shouldn't automatically blame on the furnace. 

Start with the simple things. 

Check your furnace filter. Make sure supply registers haven't accidentally been closed or blocked by furniture, rugs or other items. 

If the filter and registers look normal but airflow remains noticeably weaker than usual, the system may have an airflow, blower or duct-related problem that requires further diagnosis. 

Restricted airflow is particularly important because your furnace depends on proper airflow to operate correctly. 

Why Did My Heating Bill Suddenly Go Up?

Energy bills can obviously increase because of colder weather or changing utility rates. 

But if your energy use climbs significantly without an obvious explanation, your heating system may be part of the reason. 

Possible causes include: 

  • A dirty or restricted filter 
  • Furnace performance problems 
  • Duct leakage 
  • Thermostat issues 
  • Longer furnace run times 
  • Changes in household temperature settings 
  • Aging equipment 
  • Home insulation or air leakage 

Instead of looking at only one bill, compare your energy use with similar weather periods when possible. 

If the furnace also seems to be running longer, heating unevenly or behaving differently, those clues together can be more meaningful than the utility bill alone. 

How Old Is Too Old for a Furnace?

There isn't one birthday when every furnace suddenly needs to be replaced. 

Age is just one part of the decision. 

An older furnace that has been maintained and is operating safely may still have usable life left. On the other hand, recurring repairs, declining comfort, significant efficiency concerns or safety issues can make replacement worth considering. 

Rather than replacing a furnace simply because of its age, we recommend looking at the complete picture: 

  • Overall condition 
  • Repair history 
  • Current repair cost 
  • Safety 
  • Comfort 
  • Energy consumption 
  • Availability of replacement parts 
  • Expected remaining equipment life 

A good HVAC professional should help you understand both repair and replacement options rather than automatically assuming older equipment must be replaced. 

What Can Homeowners Safely Check Before Calling an HVAC Company?

There are several simple things homeowners can check without taking the furnace apart. 

First, confirm that your thermostat is set to HEAT and the temperature setting is above the current indoor temperature. 

Then check: 

  • Is the furnace receiving power? 
  • Is the furnace switch on? 
  • Is the filter excessively dirty? 
  • Are supply and return vents open and unobstructed? 
  • Are your thermostat batteries good, if your thermostat uses batteries? 
  • Has a breaker tripped? 

Beyond basic homeowner checks, furnace troubleshooting can quickly involve electrical components, combustion equipment, gas controls and safety devices. 

That's generally where DIY troubleshooting should stop. 

Watch: Simple Furnace Checks

The Air of Authority was created to help homeowners better understand their heating and cooling systems and includes HVAC advice from the same local experience behind One Hour Heating & Air Conditioning of Johnson County. 

When Should You Stop Running the Furnace and Call a Professional?

Some heating problems can wait for a convenient service appointment. Others shouldn't. 

Stop operating the system and seek professional or emergency assistance when appropriate if you experience: 

  • A carbon monoxide alarm 
  • Symptoms suggesting possible carbon monoxide exposure 
  • A gas smell 
  • Smoke 
  • A strong electrical or burning-plastic odor 
  • Signs of overheating 
  • Repeated furnace shutdowns 
  • Unusual combustion behavior 
  • Serious electrical problems 

You should also schedule furnace service when you notice recurring short cycling, new noises, weak airflow, uneven heating, increasing operating costs or other significant changes in furnace performance. 

You know what normal operation feels and sounds like in your home. A noticeable change is often the first indication that something deserves attention. 

Furnace Help for Johnson County, Kansas Homeowners

Kansas weather can change quickly, and once cold weather settles into Johnson County, a dependable heating system isn't something you want to question. 

One Hour Heating & Air Conditioning of Johnson County provides furnace repair, furnace maintenance, heating diagnostics, and furnace replacement and installation for homeowners throughout Johnson County, Kansas, including Olathe, Overland Park, Lenexa, Shawnee, Gardner, Leawood, Prairie Village, De Soto and surrounding communities. 

Our goal isn't simply to get the furnace running. It's to help homeowners understand what's happening with their heating system so they can make an informed decision about their home. 

If your furnace is making an unusual noise, cycling repeatedly, producing an unexpected smell or simply isn't keeping your home comfortable, having it checked before the problem becomes larger can provide valuable peace of mind. Learn more about heating and HVAC service from One Hour Heating & Air Conditioning of Johnson County.

Sources & References 

  • U.S. Consumer Product Safety Commission — CO Alarms: https://www.cpsc.gov/Safety-Education/Safety-Education-Centers/Carbon-Monoxide-Information-Center/CO-Alarms 
  • ENERGY STAR — Maintenance Checklist: https://www.energystar.gov/saveathome/heating-cooling/maintenance-checklist 
  • One Hour Heating & Air Conditioning of Johnson County: https://www.onehourheatandair.com/johnson-county/ 
  • One Hour Johnson County — Areas We Service: https://www.onehourheatandair.com/johnson-county/areas-we-service/ 
  • One Hour — Furnace Services: https://www.onehourheatandair.com/services/heating/furnaces/