Maryland Heights, Missouri
11509 Dorsett Rd
Maryland Heights, MO 63043
(314) 731-0404

5 Signs Your Commercial Furnace Needs a New Heat Exchanger September 27, 2019

Maryland Heights, Maryland Heights
5 Signs Your Commercial Furnace Needs a New Heat Exchanger, Maryland Heights, Missouri

A heat exchanger is what your commercial furnace uses to create warm air. Specifically, this part channels a flame through a series of tubes to heat incoming air that is blown throughout the ventilation system. While heat exchangers can last about 10 to 20 years, they can break and put employee safety at risk, as well as impair furnace performance.

5 Indicators of a Bad Heat Exchanger

1. Carbon Monoxide Leaks or Strange Smells

Cracked or broken heat exchangers can emit harmful gasses—including carbon monoxide. If your building’s carbon monoxide alarms go off, evacuate the building and have the equipment inspected to determine if a broken heat exchanger is to blame. Strange odors can also indicate a gas leak and demand immediate attention. 

2. Visible Cracks

If your furnace is not producing reliable temperatures, shut off the equipment and look at the internal components. If you spot cracks or holes in the heat exchanger, replacement is necessary. Keep in mind that cracks can be small and may not always be visible.

3. Soot

furnaceAs you inspect the internal furnace equipment, look for the presence of soot buildup along the interior surfaces. Soot is a sign that the system is not combusting fuel properly, which may be due to a cracked heat exchanger.

4. Water on the Floor

When a heat exchanger is cracked, increased air and heat can cause condensation to collect inside the equipment. Eventually, the moisture will leak onto the floor around the base of the equipment. If you notice unusual puddles near the furnace, call a professional to determine the source.

5. Flame Appearance Changes

If your furnace is functioning properly, the burner flame should appear steady and blue. However, if the heat exchanger is damaged, the flame can take on a yellow appearance and flicker.


Given the dangers of a worn heat exchanger, it’s important not to ignore any of the above warning signs. Instead, turn to our trusted professionals at Lindbergh Commercial Services. Equipped with years of experience and up-to-date tools, our team is qualified to maintain, repair, and replace commercial appliances in the St. Louis County area—including furnaces, air conditioning units, and walk-in coolers. To learn more, visit our website. If you’d like to schedule an appointment with an HVAC contractor, call our Maryland Heights, MO, office at (314) 731-0404.