A furnace is a machine that usually heats your house by burning fuel, like natural gas or propane. It’s quite an ingenious device, but the downside of this modern convenience is that furnaces are prone to developing rust on structural components. It’s important to understand why this happens to keep it from getting out of hand. If you’re not familiar with rust, think of it as a brownish-red metal oxide that occurs when iron, steel, or other ferrous metals are exposed to an oxidizing agent. Water is usually the culprit. In this article, we have narrowed down to reasons why your furnace has rust.
1. Air Leaks in the Furnace
Air leaks are probably the number one reason why your furnace has rust. It’s important to check the air vents on the inside of your furnace, as well as those on the outside of your house. These areas allow fresh air into the unit and must have a maintenance-free seal for efficient ventilation. Moreover, if you see a welded seam where a pipe meets a duct or a crack in a pipe, it may indicate a potential leak.
2. Air Leaks in the Ductwork
Those who have ductwork in their home, especially in multiple floor levels, are also susceptible to air leaks. Like furnace vents, the joints where ductwork meets walls need pinpoint seals for optimal performance. Make sure there are no cracks or gaps in the ducts themselves. If you notice any, use the same type of caulk to seal a bathtub since it is made to withstand high temperatures and humidity.
3. Water Damage
Another common cause of rust is water damage. If your furnace is exposed to freezing temperatures, it may develop moisture in the ductwork due to condensation. Or, if you have a unit with integrated ventilation, chances are the outdoor unit is leaking condensation where it meets the room’s concrete or tile floors.
4. Humidity and Moisture
Moisture can cause rust to form on the outside of your furnace. For instance, if your furnace doesn’t have proper ventilation, it may be exposed to an excessive amount of moisture for prolonged periods. This can potentially lead to rust or corrosion. The same is true in areas with high humidity levels in the air. Every inch of yearly exposure to one inch per year is enough to cause rust in one year.
5. Rust From the Ground
A frequent cause of rust in a wall furnace is when a pipe in your house sinks into the ground, in which case water flows under the pipe and may lead to rust. This can cause mildew at the end of a pipe near an exterior wall. An example of this is when a water main runs under an outside wall and changes pressure. This can also cause rust around an outdoor unit to form, especially if no ventilation is provided.
6. Old Age
One of the reminders that it’s time to replace your furnace is rust on its components. While some rusting around screws or pipes is normal, if your furnace is continually exposed to moisture for months, it may cause corrosion. As you can see, there are many ways for rust to form on your furnace, and it’s important to keep it in check, so you don’t have to replace or repair it prematurely.
7. Overlooked Maintenance
The many reasons why your furnace has rust may also include neglecting to maintain it. A lack of cleaning and replacing the furnace’s filters could accumulate dust and debris inside its components, increasing its susceptibility to rust and corrosion. Replace your furnace’s filters at least once every three months to keep it running efficiently. For furnace maintenance and repair in Jamesville, NY, and surrounding areas, contact Holbrook Heating & Air Conditioning for assistance.
8. Unusual Temperatures
Another reason why your furnace has rust is when you turn it up in unusually high temperatures. If your furnace can’t keep up with the temperature rise in the walls and ductwork due to a malfunction or leak in its components, it could cause them to rust and corrode faster than normal.
9. Leaking Water Tank
Another likely cause of your furnace’s rust is when it has a cracked or leaking water tank. These water tanks are made of metal, which means they are susceptible to rusting when exposed to moisture for an extended period. If this is the case, it may have already caused your furnace to start rusting around its components. Clean the tank and change its filters regularly, in addition to addressing any leaks that have developed.
10. Dirty Condensate Lines
Your furnace has a condensate line that carries water from the outdoor unit to the inside of your house, as well as from your indoor unit. If you malfunction this system, it could cause rust on pipes and other components. If you notice rust, call a professional who can inspect and clean this system for you.
11. Unvented Hot Water Heater
If you have an unvented water heater, it’s connected to the wall furnace via a shared vent. If this vent is damaged or insufficient, it can cause condensation in the furnace and rust to develop on its components. You can prevent this scenario by hiring a professional who will be able to inspect your furnace and water heater’s venting system.
12. Improper Installation
The reasons why your furnace has rust are sometimes due to shoddy installation. This can include improper placement of the unit or the use of faulty components. This is why it’s important to hire a professional furnace installer to minimize damages and ensure you’re receiving the best service possible.
13. Combustion Gas Reaction
A combustion gas reaction occurs when there is too much dust within the system. When this happens, rust forms on the inside of the furnace. Clean the unit regularly with a high-quality cleaning solution that can dissolve or avoid rusting components.
14. Leaking Gas Lines
An often overlooked factor is the quality of gas lines. If your gas lines are rusty or corroded, you may leak. This is especially true for steel pipes since they are more prone to corrosion than other materials. This can cause rust to form on your furnace’s components, increasing its chances of malfunctioning or breaking down prematurely.
15. Furnace Exhaust Issues
A common cause of a furnace’s malfunction is a faulty exhaust system. If your furnace is receiving too much moisture from the air, it could lead to corrosion in its components. Work with a professional to ensure you have proper attic ventilation.
16. Deteriorating Refrigerant Lines
The refrigerant lines in your furnace connect its compressor to the outdoor unit. These lines are made of plastic, which means they are susceptible to deterioration over time. If they break or split, moisture can leak into the system, which increases the risk of rust forming in the walls and ductwork within your home. When this happens, it may lead to rust on components like evaporator coils or blower fans.
We don’t want you to hate your furnace when it comes to your home. However, if the furnace is rusting, it’s time to replace it before anything else happens. The best way to minimize any damage or problems is by hiring our professional technicians who will inspect and repair your furnace, so it runs properly again. For AC maintenance and installation, water heater installation, indoor air quality, and HVAC installation and repair in Jamesville, NY, and surrounding areas, contact Holbrook Heating & Air Conditioning today.
