Furnace Rust - Causes and Solutions

Homeowners who don't face problems like basement flooding or water leaks may never think of a scenario like Furnace rusting. The fact, however, is that Furnace rust does not only take place in the cases mentioned above. There can be a number of other reasons when this can occur. Furnace, overall, is a reliable HVAC appliance, which if maintained properly can last for up to 20 years or more. But as the Furnace ages, it corrodes whatsoever. An ageing Furnace often shows rust problems too. So if you wonder why and how Furnace rusting occurs, you will find this blog beneficial. 

What is Rust?
Before we begin, learn what rust actually is. Rust is actually an oxide which forms when iron/metal combines with moisture/water and oxygen. This causes a chemical reaction which has the potential to damage an entire appliance severely regardless of whether it's new or old. A rusting furnace is a danger sign and that is because it can cause combustion gases to enter your home especially in case of rusting of the heat exchanger and improper venting issues that are resultants of furnace rusting.

So if your Furnace is rusting and is also old, the first to do is to call a professional to inspect the system and suggest whether it is the time to go for replacement or to have a repair. But if your system isn't an aged one and is still rusting, here are the possible reasons and solutions.

Furnace Rusting - Causes & solutions
Cause#1: Water leaks and high humidity  
Water leaks from pipes around the Furnace can cause dampness resulting in rust over time. The rain coming from the vents can cause moisture too. Moreover, unmaintained humidity in the home which finds its way into the Furnace through the duct, is often times the reason of furnace rusting.
If you're living in a locality with constant problems like basement flooding, consider investing in basement waterproofing and fix any pipe leaks as soon as they occur. To resolve the humidity problem, it is suggested to go for whole-home humidification systems that help control indoor humidity.

Cause#2 Leaking Air Conditioner
Air Conditioner and Furnace installed close to each other can cause dampness which is severe for the Furnace. The Air Conditioner leaks dripping or reaching the Furnace unit in any other way give birth to Furnace rusting.
Air Conditioner leaks are often caused by a leaking or cracked drain pan. Check it and fix it. If the drain line is clogged, use about half a cup of vinegar and flush it through the condensate line. This will remove any bacteria and algae causing the clog, clearing the line and resolving the leak.

Cause#3 Reaction of combustion gases
The heat exchanger is meant to convert the gas energy into heat energy. The process causes water vapours and this requires proper ventilation to not cause any unwanted reactions. With proper ventilation, everything goes fine, but venting issues can cause these combustion gases to react and cause moisture resulting in...yes, rust once again.
Check your vents to make sure the Furnace gets proper venting when it operates. If you have no idea where and how to make this sure, call a professional to fix the venting issues. As said above, improper venting can cause combustion problems resulting in CO poisoning and causing irrevocable damages. So don't take venting issues easy.

Note: If you have an aged system and you want to use it more, be sure to install CO detectors in every portion of the home. It is, nonetheless suggested to not drag systems when they are done with serving you for the promised years.