Why Does My Furnace Have Rust and How to Remove It?

You may have seen rust on the outside of your heater, on the inside cabinet, or perhaps on the components within. A furnace does not use water to generate heat in the same way as a boiler or other hydronic system. So, you may be wondering how rust can develop on it or if it’s an indication of a serious problem with the furnace. In this post, you will discover the reasons rust develops and the potential problems that it can cause.

Furnace Rust Causes & Solutions
Rust typically forms because of water. This can be caused by humidity, corrosion, or leaks. Of course, it may also form through other means. For instance, if the heat exchanger is damaged or imperfection in its design causes a leak. Regardless of how the rust forms, it will result in low energy output efficiency and drain your wallet.

If moisture enters through fissures or cracks in pipes or furnaces, it can cause small amounts of rust to form over time. Rust working its way out means you have a leak, which will have to be fixed. When rust forms on the interior surfaces of the unit, the furnace is not properly ventilated. This also leads to leaks, which results in wasted energy.

How Does Rust Occur if There’s No Water in the System?
There is some water vapor present in the air in all homes. This vapor moisture can settle on surfaces in the furnace. However, this humidity alone is not enough to corrode a furnace and cause rust. Nevertheless, corrosion will happen if there’s an electrochemical reaction between the water vapor and the metal surfaces in your furnace. These metal surfaces could be made of steel, aluminum, or copper. The process that catalyzes corrosion is called cathodic protection.

Cathodic protection is a process in which an electrical current induces the surface to rust, thereby protecting it from rusting further, and vice versa where a positive voltage causes metal to rust.

How to Prevent Furnace Rust

1. Waterproofing and Humidification: Instead of letting water in and then attempting to dry the air with the furnace, you can get a humidifier to keep humidity levels at a controllable level. This helps prevent rust from forming. Humidifiers add moisture to the home during winter months when forced-air systems are running. This also keeps smells and allergens at bay. It is far more cost-effective than combating rust later.
2. Check the Kick Panels: Kick panels are metal plates attached to the furnace unit directly above where it meets the floor. They are exposed to moisture, so rust is likely to form here. These panels will have to be replaced periodically, which is best done by a professional furnace technician.
3. Replace the Furnace Filters and Clean Them Regularly: You can also prevent corrosion with routine filter replacement and regular cleaning of your furnace filters. If air can’t get through the filter properly, moisture may accumulate inside the unit and cause rust to form.
4. Schedule AC Maintenance and Clear the Condensate Drain Line: This is an easy way to prevent rust from forming. If the drain line that carries condensation away from inside your AC unit is clogged, water will pool within it and rust your compressor over time. Scheduling for annual maintenance will help avoid costly repairs in the future.”
5. Call for Professional HVAC Service: No matter the season, call for professional HVAC service in Central Pennsylvania when you notice rust on your system. After all, if water or humidity is causing this corrosion, it will only worsen over time and cause significant damage to your home. Be sure also to inspect and clean other components in your furnace regularly to ensure reliable operation and eliminate the possibility of rust forming.

Getting rust off your furnace isn’t always easy but doing so will help maintain its efficiency. The problem with rust is it is quite easy to damage components when trying to remove it — you can cause wear on the metal and make it worse. If left alone, rust will continue to grow and become more expensive and difficult to fix over time. Luckily, if you catch corrosion early enough, it can be removed without too much effort or expense.

Is your furnace rusting? Get emergency repair and maintenance done right away. We provide furnace repair and maintenance service for your specific needs so that you may feel confident in your heating system’s safety. We also offer clean air and plumbing services. Contact HB Home Service Team (PA) to schedule service and maintenance today.