You have noticed an odd smell coming from your furnace. Until now your HVAC system has circulated clean and odorless air. What do you do now? Is it dangerous? Heating system smells don’t necessarily indicate a problem or a health risk. In fact, some heating system smells may not be pleasant, but are perfectly normal. For example, it’s common for your furnace to smell the first time you turn it on during a season. However, there are some heating system smells that indicate a leak and potential health hazard to your family. In this article, we lay out 6 common furnace smells, what they mean and what you should do about them.
If there is a chemical odor that smells like formaldehyde, your furnace most likely has a cracked heat exchanger. A cracked heat exchanger is extremely dangerous for two reasons. First, it can fill your home with carbon monoxide. Second, it can cause a fire in your home. At Miller’s Heating & Air we take cracked heat exchangers very seriously. If one of our technicians finds a cracked heat exchanger out in the field, he is required to shut down the system immediately until a field supervisor can confirm the cracked heat exchanger. We have these strict policies in order to protect our customers and home owners. If there is a chemical smell coming from your furnace call a HVAC professional immediately for a heating service appointment.
Sulfur or Rotten Eggs
Heating system smells that smell like rotten eggs or sulfur indicates a natural gas leak. Natural gas is odorless. Gas companies have added a chemical to the gas, which causes it to smell like rotten eggs and/or sulfur so home owners know when there is a gas leak. Inhaling natural gas is a health hazard, which can result in nausea, fatigue, dizziness and breathing issues. If there is a natural gas leak in your home, turn off your system immediately. Open your windows in order to increase ventilation and call an HVAC service professional for a heating service appointment. As a safety precaution, you may want to stay out of the home as a safety precaution until the problem has been fixed during a heating service appointment.
An electrical burning smell coming from your furnace indicates that it’s overheating. Wear and tear on components such as bearings and the blower motor can cause them to malfunction leading to overheating. The extra heat can melt other components in the system that are rubber as well as create sparks. If you smell electrical burning, immediately turn of your system in order to prevent a fire. You will need a trained professional to assess your system during a heating service appointment and repair it before it can be safely used again.
A burning oil smell only applies to home owners that have an oil furnace. Items can fall next to an oil furnace pilot light and catch on fire. There is a higher likelihood of this occurring if your oil furnace is in your basement. Make sure to keep debris and items far away from your oil furnace to prevent them from catching on fire. Another possible cause is an issue with the oil and the burner. If the burner doesn’t catch all of the oil, it can create an oil fog. If this catches on fire, it can cause a burning smell and even smoke. Lastly if you spill while refilling your oil tank and a smell may linger for a few days. If it continues past that period, you should have an HVAC professional who works on oil furnaces investigate the issue during a heating service appointment.
The smell of dirty socks is never pleasant. It’s especially unpleasant when it’s circulated throughout your home. What is the culprit? When your furnace coils cycle between heating up and cooling down, it creates condensation that allows bacteria to grow. Bacteria builds up in your system over time and causes the smell. An annual maintenance completed by trained technician should take care of this problem. During an annual maintenance, your furnace coils are cleaned. It is also important to keep up on changing your furnace filter regularly.
Dusty or Musty
Dusty and/or musty heating system smells are completely normal. Your furnace is not used during the warm months. Dust and dirt build up on your furnace and in your duct work when it’s not in use. The first time you turn on the furnace it will most likely smell dusty or musty. The dust and debris are heated and/or burned up when the furnace is turned for the first few times of use during a season.
Have your furnace inspected annually by Miller’s Heating & Air to look for faulty components, general wear on the unit and a cleaning of your unit. By having an annual service, you have peace of mind that you’ve done what you can to make sure your central HVAC unit is ready for the year ahead.