Rust is a common form of corrosion, and when you can see it on your furnace, it can be an indication of a potentially serious issue. The most obvious reason why you would see rust is that there is moisture which has come into contact with your furnace. This situation will not remedy itself and needs attention in order to prevent the corrosion process from developing any further. Here we will explore the rust issue and explain why seeing rust on your furnace means that you need professional assistance as soon as possible.
How Rust Develops:
There are a number of ways that rust can develop on your furnace. It could be the result of water vapor caused by combustion. The combustion process generates heat, but as the vapor and gasses move from the warmth of the burners towards the flue, it is possible that they can cool back into a liquid state, producing moisture. This is not usually a problem since most systems have proper ventilation, which allows any water to be directed out of the system. Unfortunately, if your system is not properly ventilated, moisture can develop which can corrode the metals used in the flue and heat exchanger.
Rust can also be the result of a leak in your air conditioner. When you have a furnace and air conditioning system, typically the air conditioner’s evaporator unit is mounted above the furnace. The coils inside the evaporator unit can sometimes drop water, which can land on the furnace. If there are any issues with the condensate array, it can also allow water to leak onto the furnace. Even a small amount of water can cause a significant rust problem, so the underlying issues need to be dealt with promptly.
The rust could also be caused by moisture developing inside the ductwork. Moisture can infiltrate the ductwork from rain and excessive humidity, especially if your ductwork system has cracks or holes. The water can travel through the ducts into the furnace and furnace cabinet, causing rust to develop. Additionally, the cracks and holes in your ductwork is likely to be compromising the efficiency and performance of your heating system. Once the ductwork is repaired, you are likely to notice an improvement in the comfort level inside your home and lower energy bills.
Correcting the Problem:
Although homeowners may have experience dealing with minor rust issues around the home, it is important to understand that the rust is merely a symptom of an underlying issue. While a small amount of rust is not particularly problematic, it is an indication that your heating system requires attention. When you notice rust on your furnace, it is a good idea to call in a professional HVAC specialist. Experienced technicians can assess your system to determine the source of the moisture and correct the problem. This will prevent further rust from developing and allow the initial problem to be treated. Rust can spread quite quickly, so it is important that your furnace is examined as soon as possible.