HVAC Emergency: Identifying the Severity of a Furnace Issue

September 21, 2023

HVAC Emergency: Identifying the Severity of a Furnace Issue

by Stewart Unsdorfer


Furnaces generally operate without incident when properly installed, tested, and maintained by a HVAC professional. But there may come a time you need to know the difference between regular furnace repair service and emergency furnace repair.

If you live in the Cleveland area, you understand the furnace emergency in the dead of winter. Some problems are more threatening than others and require more immediate attention. With a little investigation, you'll find that some complications are minor to fix, and others require the expertise of a professional.

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Furnace Emergencies - When It's Time to Call in a Professional

1. Electrical Issues Seem to be the Problem

Electricity plays a critical role in how your home operates. You rely on your home's electrical system to provide power when you need it, and that could be powering your heating and cooling systems.

Your lights should not flicker when your system turns on. Electrical issues should be addressed by a professional. Understanding the basics of your electrical system can help you identify and avoid potential hazards, but leave nothing to chance.

This video from the Electrical Safety Foundation International (ESFI) provides a brief introduction to the different components of your home's electrical system, includes tips for identifying electrical safety hazards, and explains some advanced electrical technologies that can make your home safer.

ESFI.org Electrical Safety Foundation International (ESFI), Home Electrical System Safety, via YouTube

Do not put yourself or someone else in danger by attempting repairs you are not qualified to do. The Electrical Safety Foundation sites:

  • Electrical failures or malfunctions were factors in an estimated 43,700 home fires
  • These fires caused 430 deaths and 1,620 injuries
  • Causing approximately $1.5 billion in property damage

Having a qualified and trustworthy HVAC professional "on call" can be a life-saver when your furnace equipment calls it quits.

2. Furnace is Making Unusual and Loud Noises

Sometimes a furnace may be running fine, but loudly. If you can tell the noise is a result of the air running through the ductwork, one solution may be to insulate your ductwork to cut down on the noise. If the actual furnace system is making odd noises, this can occur when the pilot light is improperly adjusted or the blower motor lubrication ports need oiling. There may also be an issue with the belts or even the burner.

What are the different noises coming from your furnace?

a. Pinging or popping sounds - could be thermal expansion- the ductwork expanding and contracting as it heats and cools.

b. Rattling noises - loose panels may need to be tightened.

c. Squealing noises - could be a belt that connects the motor to the fan slipped. Or the belt needs replacement.

d. Grinding sounds - probably time to call a furnace repair technician. The motor bearings need repair. (source)

When to call a professional: While it may not seem like an emergency, you should have furnace system noises checked out by a service technician. Early detection of a problem may save you from further damage and a larger repair bill in the future.

3. HVAC System is Turning On and Off Rapidly

In the case of a furnace turning on and off again too quickly (rapid cycling), many causes can exist. The first may be a dirty or worn-out air filter. If you haven’t replaced it within very recent memory, try doing so — it’s a quick and easy fix.

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Using old filters puts more stress on the compressor and can lead to mechanical failures over time.

When to call a professional: If a new filter doesn't solve the problem, you may have a more serious situation. There may be an issue with the blower motor and belts and both require the service of a professional.

4. There is an Unpleasant Odor: You Smell Rotten Eggs / Sulfur  

If you smell gas, leave home immediately.

First things first — make sure the residents of your home are safe before you try to get your problem fixed. If you smell a strange odor, everyone should leave the space immediately.

Note that you cannot actually smell or see natural gas. That’s why a substance is added to it, called mercaptan. It smells unattractive - something to the effect of a rotten egg. The smell is very distinct, so you can immediately determine if there is a gas leak in the house.

What Should I Do If I Smell Gas?  "Rotten eggs"

Don’t mess around, especially if you hear any hissing.

  • Get your family out immediately.
  • Do not turn on or off any lights – the small electrical arc created could cause the gas to ignite.
  • Do not turn on the stove.
  • If windows are open, leave them. If you are able to open a few windows on the way out the door, then do so, but quickly.
  • Do not use the phone or cell phone in your house.
  • If the car is in the garage, leave it. Starting the car could cause an explosion — so could the mere act of opening the garage door using the door opener.
  • Go to your neighbor’s or outside to call for service.
  • Consider keeping the family out of the house if the service call is delayed. Plan to stay elsewhere until the gas leak is fixed.
  • Only turn off your gas if it is safe to do so. And call an emergency team right away. [source: How to turn off your gas meter]


What to Do If You Have a Natural Gas Leak

How to Shut-Off a Gas Meter

Gas Leak Warning Signs | Is Your Furnace Leaking Gas?

5. Your Heating System/Furnace is Blowing Cold Air

Make sure the blower is clear of any debris. Also, there should be a flashing light; green or red.

If the light is green, it's okay; if red, call for service. And if there is no light, the furnace problem may be with the thermostat, the blower motor, the run capacitor, furnace control board or transformer.

This video will show you where you should start with your furnace troubleshooting. Here we explain where you can see furnace error codes and where to find the chart that explains what they mean.

Word of Advice TV, Furnace Blowing Cold Air, Where to Start, via Youtube

How to Troubleshoot a Furnace Blowing Cold Air

Furnace Blowing Cold Air? 13 Common Causes.

6. Your Flame Isn't Blue

Check the color of your pilot light flame. If your flames are closer to a yellow color, it could be a combustion problem. With combustion problems, you must be aware of excess carbon monoxide.

Carbon Monoxide is difficult to detect. It's been coined the "silent killer" for a reason. It doesn't have a smell, color, or taste. It can be found in your home from your fireplace, gas ranges, and furnaces. The build-up indoors can poison people and their pets who breathe it.  

Natural gas consists of methane and when it burns, it gives off a blue color. When you check your furnace flame, and the color is "off",  it is time to call a HVAC professional.

A combination of condensation and soot can also cause burners to malfunction. The burner assembly should be cleaned annually or replaced if the existing one is in poor condition.

7. Your Heat Suddenly Turns Off

This may not be an immediate emergency.

There are a few things you can do before calling for repair service:

  • Check your air filter - the filters keep your system clean. If it is clogged, it may cause your system to turn off.
  • Check your thermostat - Depending on the type of thermostat you have, you may need to replace the batteries.
  • Reset your home circuit breaker and more...

19 common furnace problems and how to fix them right now.

Your Furnace Deserves Your Attention

A quality furnace system is one of the most important investments you can make in your home. The system adds both value and comfort to your living space and should be regularly maintained to keep it in top working order.

Developing a partnership with a trusted HVAC professional is one good way to educate yourself about your furnace and to feel confident about any repairs you have done.

Remember, while attempting do-it-yourself repairs can be satisfying and cost-effective, it is crucial to be sure that you have the skills before attempting any work on your furnace.

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