10 Common Furnace Problems and How To Fix Them

Homeowners with gas furnaces in their homes tend to forget that they’re even there until something goes wrong. The same goes for homeowners with oil-burning furnaces. Those are the two most common types of residential furnaces, so it stands to reason that they’re also the most common to go unnoticed until something broken forces you to take notice. If your furnace is giving you problems, rest assured that you’re not alone. Any homeowner with a gas or oil furnace will sooner or later find themselves having issues with theirs. Fortunately, most issues are rather easy to fix if you know what can cause them in the first place. Here are 10 of the most common problems and ways to fix them if this ever happens to you, too:

Short Cycling

Short cycling is when your furnace shuts off and starts again before the house has time to heat up enough for you to notice. It’s usually caused by a dirty or clogged filter, especially if it’s happening all the time. A dirty filter might also be robbing the furnace of the air it needs to run properly. If you’re seeing this problem, try cleaning the filter or replacing it, and it should go away. Another possible cause is a bad wiring connection in the furnace itself. Make sure your wiring connections are all tight, otherwise the furnace might not be getting the power it needs.

Noisy Operation

Furnaces are supposed to be quiet, but if yours is suddenly very loud, you’ve got a problem on your hands. A loud furnace might be an indication that the blower motor is infected with carbon monoxide or that something is wrong with the motor itself. If so, you’ll need to call a furnace technician to get it fixed. If your furnace is just making a lot of noise in general, the first thing to do is make sure it’s not vibrating excessively. If it is, that’s a sign that something is wrong with the furnace’s mounting. If the furnace is just making a lot of noise, but there’s no vibration, it could be an indication that something is wrong with the blower wheel. If this is the case, you’ll also need to call a furnace technician to get it fixed.

Poor airflow

Poor airflow could mean that your furnace is sucking in less air than it should or that it’s not extracting enough air from the house. If it’s sucking in less air than it should, you’ll know by the fact that your home isn’t getting warm—the furnace is simply cycling on and off too quickly. If the furnace is sucking in less air than it should, you’ll know by the fact that your home isn’t getting fully pressurized. Then, when the furnace cycles on, it draws the house in too quickly. A sudden drop in pressure inside the home may cause a whistling or sucking sound. If it does, there’s an air imbalance inside your home. This is a problem because it can lead to carbon monoxide leaks.

Blower Problems

If your furnace is running, but the blower isn’t turning on, you may have a problem with either the blower or the blower switch. If the switch is bad, you can simply replace it. If the blower itself is misfiring, you’ll need to call a furnace technician to replace the blower. If the blower is turning on, but it’s not delivering a sufficient flow of air, there could be a clog somewhere in the ductwork. This is another problem that would require a furnace technician to fix.

Electronic Or Mechanical Controls Are Broken

Electronic controls and mechanical controls are different, but both are equally important when it comes to furnace operation. If either one of these breaks, you’ll have no way to control the furnace, which can be dangerous. If you have electronic control, you’ll need to call a furnace technician to perform a diagnostic check. If you have a mechanical control, you may be able to simply replace the control box.

Dirty Or Broken Filters

If your filters are dirty, the furnace won’t be able to operate properly. The same goes for broken filters. If your filters are dirty, replace them, and if they’re broken, replace them. If your filter is broken and there are shards of filter in the air ducts, you can use a shop vac to vacuum them out. Even if you can’t find all of them, it’s better than nothing.

Bad Ignition Or Pilot Light

A furnace will use either a gas ignition or a pilot light to light the burner and the gas coming into the furnace. If the burner is out, or the pilot light is out, you’ll need to call a furnace technician to get it replaced. If the pilot light is out and you know it was lit at one point, the problem may be as simple as low oxygen levels in the furnace. You can fix this by simply blowing out the pilot light.

Depleted Furnace Air conditioning (daf) Valve Or Accumulator

If the daf valve or accumulator is depleted, it won’t be able to regulate airflow properly. This will cause the furnace to cycle on and off too much. If this is the case, you’ll need to call a furnace technician to replace the valve or accumulator.

Recommendation

The best thing you can do if you’re ever experiencing furnace problems is to call a professional. A furnace technician can quickly diagnose the problem and make the necessary repairs. You can save yourself a lot of time and effort by calling a technician instead of trying to do the repairs yourself.