While it's normal for a furnace to make some noise, a different sound than usual can indicate a problem. In this case, loose, worn out, or missing parts can be the culprits, damaging the equipment in the process. If you're concerned about the noises coming from your furnace, here are a few sounds that may require professional heating repairs.

Which Furnace Sounds Require Heating Repairs?

1. Shrieking and Scraping

These sounds mean that a moving part is grinding against a nearby surface. One common culprit is a broken or loose blower wheel scraping the casing. The motor’s ball bearings can also be damaged or stuck and in need of heavy-duty lubrication. The noise can also result from a loose belt slipping against its seat, which will require an adjustment from an HVAC contractor.

2. Banging

Quiet popping is normal when the system’s air ducts shift as they heat up or cool down. However, loud bangs are an issue. These sounds can mean there’s a problem with combustion. For example, too much gas may be lighting at once, causing small explosions. This is often due to dirty burners that keep the flame from igniting quickly enough.

3. Rattling

A fast, repetitive sound like this means an object is stuck in the blower blades. Either it’s caught on the blades and hitting the casing as they spin, or it’s stuck on the sides and being hit by the blades as they rotate. 

This obstruction creates additional resistance for the blower’s motor, which has to work harder to turn the blades and will wear out more quickly. For this reason, even if the rattling is quiet, the furnace needs the attention of a heating repair professional as soon as possible.

If your furnace is making unusual noises, contact the heating repair technicians at ProTech Heat-Cool in Lincoln, MO. Having served Benton, Hickory, Henry, and Pettis counties for over 30 years, this licensed and insured company offers a full range of residential HVAC services, including repairs, regular maintenance, and installations. Call (660) 477-4328 to schedule an appointment, or visit them online to learn more about how they can keep your heating system working.