5 Common Furnace Noises That You Should Never Ignore

With the average furnace repair cost hovering around $297, and a full replacement averaging around $5,500, there are certain practices homeowners need to keep in mind.

Preventative measures like a regular servicing plan can help keep many issues from developing in the first place. This, in turn, also means that you won’t have to worry about paying for expensive repair costs or furnace replacement.

However, there are some things that you just can’t ignore.

Here are five types of furnace noises that you should never ignore, as well as how you can go about addressing them.

An Aging Machine

As they age, all furnaces are going to get noisier while they run. But, when they make repeated noises or a certain set of noises, you start to have cause for concern.

No matter the problem, if it amounts to more than tightening a panel or two or changing a filter, always call a professional. Fixing a furnace is no reason to put your safety on the line.

1. Loud Banging

This is one of the most common noises a homeowner will encounter. Primarily because it can be caused by several issues or a combination of issues, all of which are fairly serious.

Expansion and Contraction

While causing a similar noise, you can usually differentiate these banging noises from other ones caused by a gas build-up.

This issue happens more often when the furnace is cycling off. It is caused by the sealing between ducts, as well as the temperature between the various items in the ductwork.

A technician will be able to install proper insulation and correct sizing, as well as replacement filters to address any of these issues.

Dirty Burner Units

When there is a build-up of dust and dirt on the burners in a furnace, it causes a delay in the ignition process. This causes the gas to build up in the system and eventually explode when the ignition does finally come on.

Regular cleaning of the burners can solve this problem.

2. Metal on Metal

The scraping of metal on metal is an easily recognizable noise. If you hear this coming from your furnace when operating, there are a couple of situations that may be occurring.

First, the blower fan for your furnace may have become loose. Because it is loose, it is now hanging improperly and is hitting against the casing. This is an easy fix, as it is not completely broken.

A more serious cause is when the entire housing is broken. In that case, you’ll need a complete replacement. In either case, make sure to immediately shut the furnace off and contact an HVAC professional.

3. Screeching and Squealing

Quite the startling noise, screeching noises often make the problem sound much worse than it is. That being said, they still need to be inspected and fixed. Generally, they come down to issues with one of three things.

In belt-driven motors, the blower belts can become damaged or loose. If they do, the next time the furnace runs, it can cause squealing noises. The blower motors themselves may be malfunctioning, as well.

Bearings and other moving parts may also become dry and require lubrication. It may require a cleaning service to remove debris and grime. However, this can be avoided with a solid maintenance plan.

4. Rattling and Clicking

With a rattling noise, the problem can either be simple or potentially dangerous if not addressed. In most cases, it is a loose panel or screw. You can turn the power off and check for any loose items.

However, if it is not either of those things, the situation can be much more serious. It could be a crack or leak in the heat exchanger for your furnace.

A damaged heat exchanger can leak carbon monoxide into the home, which can even lead to death. If you do not find the solution right away, make sure to contact a repair company immediately.

Small bits of clicking is normal when a furnace turns on or off, and aren’t anything to worry about. However, if you find that the furnace continues to click for a minute or longer, this is a problem.

Clicking often indicates a problem with the electrical controls of a furnace. This means that the ignition, gas control, relay, or wiring may be compromised.

Make sure to call a professional. Do not attempt to fix this yourself!

Another common issue can be the thermostat, but thankfully, this is also an easy fix.

5. Deep Rumbling

We have looked at banging, rattling, and now rumbling. The primary issue that comes with a deep rumbling noise is a pilot light that needs readjustment.

You can make note of this by checking the color of the flame on your furnace. A properly operating, clean flame should be blue. At times, there may be a slight yellow tip.

If you find that there are any other colors in your pilot light’s flame, this is cause for concern. Make sure to address it immediately.

Other than the pilot light, loose debris, ductwork, broken fan blades, or an issue with the furnace’s motor can cause rumbling type noises.

Never Ignore Furnace Noises

As you can see, an expert needs to investigate all types of furnace noises. The situation might not seem serious, but you never want to take the risk.

Aside from having a huge bill, some scenarios can also turn deadly.

Remember to partner up with the experts at Walrath HVAC for regular servicing. When you do, you won’t have to worry about any of these furnace noises sneaking up on your system again.