What There Is To Know About Gas Furnace Troubleshooting

There are several problems that your gas furnace may present to you, but many of them can be solved easily, which is why it is important to be proficient at gas furnace troubleshooting.

There are various troubleshooting tips that may save you a service call, but it is advised that if you have any doubts about the repairs or repairing process you should call a qualified gas furnace specialist. Any repair not done properly may threaten the lifespan of your gas furnace.

Gas Furnace Troubleshooting: Heat Problems

There are two main heating problems you may encounter with a gas furnace:

1. The furnace may produce insufficient heat

2. The furnace may produce no heat whatsoever

Insufficient Heat

It is easy enough to tell when a gas furnace is not producing enough heat for your liking. The gas furnace troubleshooting that should take place in these instances involves determining whether it is due to either:

  • A dirty furnace air filter, or
  • A gas furnace burner that is dirty or needs adjustment

If you have identified a dirty air filter as the problem, it is perfectly possible to replace it yourself as long as you research the method. The gas furnace burners, on the other hand, will require professional attention, and it would be best to call a technician.

No Heat

A gas furnace that produces no heat at all is obviously a serious problem. The gas furnace troubleshooting that you should employ in this situation involves asking yourself the following questions:

  • Is the thermostat set too low or malfunctioning?
  • Are any essential components, such as a fuse, tripped or blown?
  • Is the valve releasing the gas into the system closed?
  • Is the pilot light out?

Once you have established the cause, you should be able to solve the problem yourself. Check the temperature settings and try adjusting them. You could clean out the thermostat, reset tripped or blown components or relight the pilot light, depending on the exact cause of the problem.

Gas Furnace Troubleshooting

Gas Problems

A problem you may encounter with your gas furnace is aGas Furnace Troubleshooting situation where the furnace comes on and off too quickly. The gas furnace troubleshooting involved here requires identifying whether:

  • The furnace air filter is dirty,
  • The blower motor has a problem, or
  • The thermostat has a problem

To deal with this you could adjust the thermostat heat anticipator. There are several thermostat problems to keep in mind, so this may require more intensive gas furnace troubleshooting. Air filters can easily be replaced. In the case of a problem with the blower, it is usually helpful to oil the motor lubrication ports. Check the belt on the blower and make sure that it 100% operational.

Blower Problems

As indicated earlier, you may have some problems with your blower. For example, it may never turn off. The gas furnace troubleshooting you do in this instance should lead you to ascertain whether it is due to:

  • An incorrect setting on the thermostat fan, or
  • A faulty fan control switch

These problems have easy solutions. Settings can be changed, and fan switches can be replaced, either on your own or with the help of a technician.


One of the most annoying gas furnace troubleshooting problems you may encounter is in discovering what makes a noisy gas furnace noisy. This could be due to:

  • Slipping blower belts or parts that need oiling. This will usually create a high-pitched squealing sound.
  • A poorly adjusted pilot light may cause a low rumbling sound when the burners are off.
  • Dirty gas burners may cause a low rumbling sound when the burners are on.

Bits that need oiling should be oiled with light weight oil, and the belt should be checked to ensure that it is at the correct tension and should be adjusted if necessary. If the pilot light needs adjusting, then adjust it, but again, if the burners are the problem you will need to have a technician adjust or clean them.

Furnace Pilot

One problem you may experience with your gas furnace is the pilot light going out. Luckily there are gas furnace troubleshooting methods available to help you. This may happen due to:

  • A strong draft
  • A dirty orifice
  • Dirt on the gas tube
  • A faulty thermocouple

There are many online resources to help you deal with this issue, so make sure you consult them before attempting any gas furnace repairs.

Things You Can Do Before Calling Help

As you can tell from the above overview, there are a few basic things you can do yourself before calling a technician to help you with you gas furnace troubleshooting issues. Start by asking yourself some basic questions:

Is your filter dirty? As we have seen above many gas furnace troubleshooting methods involve ascertaining whether or not the filter is dirty. Taking the time to check this could save you a lot of time and effort later on.

Have you tried resetting your gas furnace? As you would do with a computer, try hitting the reset button your furnace in the event that it does not function properly. This may solve any problems you are experiencing and it may save you a lot of time.

Is the door cover on properly? This is a very basic gas furnace troubleshooting tip, but it is also a very important one, as your gas furnace will not work properly if the door is not on correctly.

Is your furnace turned on? Yes, I know you are not an idiot, but it may be worth checking that the furnace has not somehow been turned off by mistake.

Are any fuses blown or circuits tripped? A lot of the gas furnace troubleshooting advice outlines above is related to blown or tripped components. Even if you can’t replace them yourself, it may be worth finding out if this is the cause of the problem in order to speed up the repair process and inform the technician.

Are the thermostat settings correct? Again, this may seem obvious and simple, but it is amazing how often the problems people experience with their gas furnaces are merely due to incorrect settings.

There are several issues that you may experience with a gas furnace, but most of them are easily solvable and easy to deal with. Be aware of the various gas furnace troubleshooting tips available, and try to help yourself when you experience problems.