Residential Plumbing & HVAC Experts

Funky Furnace Noises Decoded

Your furnace shouldn’t talk to you. Furnace noises can usually be traced to specific issues or conditions. Here’s a breakdown of some of the most common furnace noises and what they could mean.


This could be caused by a loose or disconnected blower fan belt. If it turns out to be the case, you need to get it repaired as soon as possible by a certified HVAC specialist. If you don’t have it taken care of, it can strike other furnace components and cause expensive damage. Investing in a preventive maintenance program is a smart idea to keep this from happening in the first place.


This may be due to loose cover panels, which can sometimes work themselves loose. A simple tightening of the screws might get rid of the rattling noise. If not, further investigation might be needed to determine the source, because rattling is not supposed to happen.


Does your furnace sound like it’s going to blow up every time it kicks on? Aside from this being a frightening sound, it’s definitely not normal. If you have a gas furnace, you likely have built up grime on the gas jets. You’ll need to call in a professional to take out the burners and clean them, before your furnace quits on you altogether.


If your furnace clicks when it kicks on or off, that’s okay. But if you hear repeated clicking, then you could have a defective control panel or a leaking gas valve. Either way, this needs to be checked out and fixed by an HVAC technician.


Grinding furnace noises are not normal. It’s possible that the motor bearings are worn out. It’s best to shut your furnace off if possible and get a professional in as soon as possible to check it out. Continuing to run your furnace in this condition will eventually cause the motor to burn out, which could lead to expensive repairs.

Give our technicians at Sherlock Plumbing, Heating & Air in San Diego a call. We can troubleshoot your furnace’s mystery noises and get it working efficiently again.