Does Rust on a Furnace Mean It's Time for Repair?
Does Rust on a Furnace Mean It's Time for Repair?

January 30, 2015


Rusting is a term that describes the effect of a chemical process in which water, oxygen, and iron or an iron alloy like steel react to form iron oxide. If your furnace begins to rust over time, it’s never a good sign. Unfortunately, it’s sometimes cause to replace the entire furnace. But at other times, rust is to be expected over time, and replacing a single component may just solve the problem. Read about when a rusty heating component must be replaced and why it’s sometimes best to say goodbye to the entire unit in today’s guide.

The Problem with Rust

The issue with rust on any metal is that rust leads to corrosion. Rust essentially eats away at the iron alloy it covers, to the point that the strong metal becomes more of a flaky powder that chips away and allows the metal to develop holes. It also makes it more difficult for moving metal parts to turn, as they get stuck when they move up against one another. Rust is particularly problematic for a component like the heat exchanger, where holes in the metal could allow for a carbon monoxide leak into the home.

Are Repairs Still Possible?

While it’s not feasible to clean off a rusty spot or try to patch it up, there are some circumstances under which only a single part needs replacement. One common example of this is if the flue pipe rusts. It’s actually quite normal for the flue pipe to become rusty over time, and a homeowner shouldn’t have to replace this pipe very often. Flue pipes rust because of the combustion process. The gases that form as a result of combustion include water vapor, and when this come into contact with the pipe that vents combustion gases to the outdoors, it can cause corrosion in the pipe.

Other times, however, the furnace unit itself will need immediate replacement, particularly if there is a looming safety issue. But it makes more sense to replace a unit with a little bit of rust on it now than to wait for a safety hazard to occur or for parts of your unit to break away and create a mess for your home.

At Bronco Plumbing Heating and Air, our experts can detect rust during a routine maintenance. When you notice problems with your furnace, call for our heating repair service in Elk Grove. Call our experts today!