St. Louis winters are unpredictable. Temperatures can drop to 15 degrees one week and climb to 55 degrees the next. This freeze-thaw cycling causes expansion and contraction in metal furnace components, including pilot assemblies. Thermocouples that are slightly loose or misaligned can shift position as the metal expands and contracts, moving the sensor away from the pilot flame. When this happens, the thermocouple cannot generate enough voltage to keep the gas valve open, and the pilot shuts down. Homes in older neighborhoods with original furnaces are especially prone to this issue because decades of thermal cycling have loosened mounting hardware.
St. Louis homeowners need technicians who understand how local weather patterns affect heating equipment. We have worked on furnaces in Tower Grove, Soulard, the Hill, and Lafayette Square for years. We know which furnace models are most susceptible to pilot light problems and which components fail first. We also understand the venting challenges created by old masonry chimneys common in pre-war homes. Choosing a local HVAC company means you get a technician who has seen your exact problem before and knows the fix.
