The gas furnace, in most homes, can be a source of many unpleasant smells. One of the more common is the smell of burning. If you notice this smell anytime your furnace comes on, there is a good chance that your evaporator coil needs to be cleaned or replaced. This article explains why this happens and what you can do about it.
9 Reasons Why Furnaces Emit Burning Odor When Turned On
1. Condition of the evaporator coil
The evaporator coil is placed in an airtight duct, or plenum, and is responsible for the heat production of the furnace. It contains a series of copper tubes that take gas from the gas valve and distribute it throughout your home through small holes in pipes. It also has a series of fins on it that are designed to absorb heat from the air and send it to each home. Over time, this coil can become corrupted due to several different factors.
2. Loose connections
If your heating system has no water valve, water heater switch, etc., and the system turns on randomly, there is likely a loose connection. You will need someone to inspect these connections and tighten them if necessary.
3. Gas odorant is added to the gas
Some homes will have a gas odorant installed on their furnace. This odorant gives off a funky sulfuric smell designed to alert you when the gas leaks through leaks or cracks in your furnace. It will happen gradually, but a burning smell will always accompany it. If you notice that these smells occur at specific times of the year, this is a good indication that your evaporator coil needs to be cleaned or replaced.
4. Defective gas valve
If your heating system has no gas odorant and the furnace happens to turn on right when you are in there, there is a good chance that the gas valve is defective. A gas valve should never release any odor; when it does, it will always be accompanied by a burning smell. If you notice that the smell occurs just at specific times of the year, you may want to call in a professional to check the valve.
5. Defective electronic thermostat
The electronic thermostat is located internally in your furnace and is responsible for turning on your system when it reaches a specific temperature. If it fails, the heating system will not turn on. When you smell a burning smell, that indicates that your electronic thermostat needs to be replaced.
6. Defective fuel nozzle
The fuel nozzle is located outside of your home and is responsible for opening the gas valve at the correct time. If the nozzle has stopped functioning correctly and you notice a burning smell, it needs to be replaced immediately by a professional.
7. Defective floor register
The floor register is also located outside your home and will be responsible for distributing gas throughout the house when it completes its gas delivery cycle. If you notice a burning smell, it is a good idea to check the register at that location.
8. Leaks in the gas piping
A burning smell will usually accompany gas leaks, or they can cause the heating system to turn on suddenly and without warning. If you notice that your house smells like gas when you reach the basement or crawlspace, there are likely leaking pipes somewhere inside your home. To fix this problem, you need to call a professional plumber to diagnose and repair any leaks.
9. Loose connections
If your heating system has no water valve, water heater switch, etc., and the system turns on randomly, there is likely a loose connection. You will need someone to inspect these connections and tighten them if necessary.
Over time, your furnace can start to have a burning smell that is not caused by a gas leak. In most cases, this smell is caused by the evaporator coil of your furnace. If you notice it for the first time when you turn on the heat, it is recommended that you call in a Riverside furnace repair professional.
Recent Comments