Furnace Won’t Turn On: Common Reasons And How To Solve Like PRO?

Furnaces, also known as ‘boilers’, are the heating units used in central heating systems like thermostats. As we are so dependent on heat, we get stuck in a dire situation when the furnace won’t turn on.

Luckily, there are some easy fixes to this problem. You don’t need to be technically sound to solve such easy-to-fix issues.

You will find why you are facing this trouble and exactly what to do about it from this in-depth guide. Keep reading!

Why Won’t My Furnace Turn On?

furnace won't turn on

If your furnace stops working, it is necessary to explore different possibilities and identify the fault. There could be several reasons why the furnace at your household will not turn on or malfunction.

Let us explore a few key reasons why that could happen:

  • Wrong Setting In Thermostat

If the thermostat isn’t set up correctly or you have a blank thermostat, it may not feel necessary to turn on the furnace. This means that hot air won’t dissipate.

The thermostat regulates the activity of the furnace and will only turn on when the user sets the temperature correctly.

  • Furnace Clicking but Not Turning on

This usually happens due to a faulty pilot light. The pilot light acts as the ignition sensor of the furnace. It acts as a source of ignition as well.

This sensor may not work if it is dirty or jammed. In other cases, the sensor might be damaged or worn out, needing replacement.

  • Problems in Gas Line or Electric Connection

A gas furnace requires both a working electric and gas line. Make sure that the gas line does not have defects and has appropriate supply and electricity is available in necessary wattage.

In the case of an electric furnace, check the electric line for possible malfunctions.

  • Clogged Filter Or Vents

Over time, it is natural for the furnace and the heating system to get clogged by dust, microparticles, or dirt.

Check the vents and the air filter and make sure they are not filled with dust. Also, make sure that the vents are not blocked by any obstacles like furniture.

  • Faulty Power Connection

In several cases, there could be a faulty power connection. An example would be a tripped circuit breaker obstructing electrical flow.

Fixing Malfunctioning Furnace: Steps And Alternatives

fixing if furnace won't ignite

Since you know what a furnace is and what it is made of by now, you can take preliminary steps to fix it in case of a problem.

These steps are described in a general manner and should apply to nearly all furnaces. There could be slight variations in certain units, but the core steps are constant.

Some ways of fixing a furnace that will not turn on are as discussed below:

Fix-1: Checking the Thermostat Settings

Often, the furnace is not working on or turning on because of thermostat settings. Check the thermostat and whether heating has been turned on.

Many new thermostats, like problematic Honeywell thermostats, show an error code if there is something wrong. The thermostat display could, in many cases, show the problem.

If the thermostat does not show errors or guide you to the problem, there could be other problems at play. Proceed to the alternative solutions in that case.

Fix-2: Check Electrical and Gas Connections

In many cases, the problem could lie in a faulty gas or electrical line instead of the furnace itself. Check the electrical line and wiring.

All furnaces, be it gas or electric, require electricity. Make sure to monitor the wattage of the electric connection and whether it is enough for the furnace to operate. Also see if the circuit breaker is tripped, in which case fix it.

An uninterrupted gas line is also key to the furnace working. Test the gas line to see if there is a sufficient supply of gas. Gas furnaces should have valves placed near the unit.

You can identify the valve by its handle or level. The valve can be disc or box-shaped and it is usually colored, for easy identification. Make sure that the valve is turned on.

You can tell if the valve closed if the handle is perpendicular to the gas pipe. In order to open the valve, rotate the handle until it is parallel to the gas pipe. This should allow gas to flow freely into the system.

If the furnace does not turn on even after opening the valve, then there could be a possible problem with the gas connection in your household.

Contact the gas provider to ensure that there are no problems in the gas supply. Checking other household appliances like a stove can also help you identify possible issues with gas lines.

Fix-3: Replace Clogged and Worn-Out Air Filter

The air filter in the furnace ensures proper airflow throughout the system. In order to regulate air temperature and heating, the filters should be replaced every two to three months.

The number of months will vary based on usage as well as the presence of dust, microparticles, etc. Household debris can also clog the air filters.

The filter is placed where air flows into the furnace. In order to replace it, take it out by hand.

There should be markings on the side regarding the model number and other specifications. When buying a replacement, buy one with the same specifications.

Once you have acquired the replacement filter, fit it in the slot where the old filter was placed.

To place it correctly, check if the frame has a directional arrow. Place the filter in such a way that the arrow faces the side of the furnace.

Changing the filter after regular intervals will allow the furnace to be more efficient and effective.

Fix-4: Check Pilot Light/Ignition Sensor

The ignition sensor works to detect flame and turn on the furnace when needed. If it malfunctions, the furnace will be turned off and will not provide heating.

This can happen due to several reasons. There can be dust or residue buildup in the sensor. That will prevent it from working properly.

Cleaning the sensor can solve the problem of the furnace not turning on.

There are a few key steps of cleaning the ignition sensor and they are laid down below:

  • Turn off the furnace by closing the valve that allows gas into the furnace. This can be done by rotating the lever until the handle is perpendicular to the gas pipe.
  • Once the furnace is turned off, locate the porcelain base. There should be a metal rod attached to it. Remove the screws with the correct screwdriver and take out the rod/sensor.
  • Use a rust-free straight-edged knife or steel wool to clean the metal rod. Do it slowly and gently in order to not detach the rod from the base.

Once you are done cleaning, carefully place the sensor back in its place and turn it on. Use the correct screwdriver again to bolt it into place.

Fix-5: Fix When My Electric Furnace Will Not Turn On

Gas furnaces are the most common furnaces we see in households. Yet, Electric furnaces are also becoming more popular due to several reasons. In many areas where gas is unavailable, electric furnaces are used.

In This point, we will discuss potential fixes for electric furnaces.

A few of the fixes more specific to electric furnaces are as follows:

  • Blown fuses are a prime reason why electric furnaces will not turn on. With regular usage, the fuses in the furnace will inevitably be busted. Check the fuses in the furnace and replace any blown-out fuses that you observe with replacement ones.
  • Check the fuse box of your household to see if the breaker attached to the furnace is turned on. In cases of overload of current, the breaker would trip. That would stop the current from entering the furnace. Flip the circuit breaker and see if the furnace turns on.

How To Be Safe When Fixing My Furnace?

turning on stopped furnace

Think of all the snowy winter mornings you spent in your warm, cozy living room drinking cocoa. Or how you walk into a store or a building on a chilly day and the warmth instantly soothes you.

Cool mornings or freezing nights; furnaces keep us warm in ways we do not notice.

While modern furnaces are built to be safe to work on, you should still exercise caution. Furnaces involve high-pressure gas, heat, and electricity. So to keep yourself safe, you should take precautions.

Some of the precautionary steps that you might want to take when fixing your furnace are mentioned as such:

  • Careful of the Lines and Wires!

Be careful of the gas and power lines. Gas leaks or cracks in the power line could cause serious injury. Be observant and check if the wires and gas lines have any abnormalities or problems.

Always turn off power and gas lines before deep-diving into the furnace for your own safety.

  • Right Tools, For the Right Job!

Before approaching the problem, make sure you have access to the different tools or implements we mentioned in our guide. This includes the right screwdrivers, cleaning materials, and other tools.

Do note that the tools you will end up needing will vary based on what furnace you have.

  • Slow and Steady!

Furnaces are highly sensitive machines with many delicate parts and pieces. So, when you work on the system, take your time, and do not rush anything.

Or else you may end up damaging the furnace or hurting yourself.

What To Do When the Furnace at Your Home Malfunctions?

Consulting a technician might seem like an easy option. Yet, having basic knowledge about furnaces and how they work can come in handy.

Firstly, being able to fix a crucial home appliance is a big plus. Secondly, it can save you money that you would pay to a technician or a service center.

You may even save some precious time by fixing certain problems yourself instead of waiting for a technician. As you have already learned how to find a fix for a furnace that will not turn on, let’s watch a nice troubleshooting video!

Furnace and Its Types

A furnace is the heating unit of a central heating system, seen in thermostats. Furnaces can be of several types, but all of them work on basically the same principle.

The furnace converts heat into the air, and then the air flows throughout the house or building through ducts.

Furnaces are of different types from different brands. But you must avoid some poor furnace brands to stay trouble-free. Now, let us look at the common ones you might encounter:

  • Gas Furnace

This is the most seen furnace in households. It uses gas from household gas lines. Gas furnaces are particularly good at dissipating heat evenly throughout the system. They are also the most efficient.

  • Oil Furnace

Oil furnaces are used as an alternative to gas furnaces in cases where gas isn’t available. They convert oil to heat.

  • Electric Furnace

Electric furnaces use electric heating elements to create and dissipate heated air. They are less efficient but could be very useful if the gas line is not available.

What is Inside a Furnace?

It is essential that you familiarize yourself with some key elements before attempting to fix a furnace.

The key parts of a furnace are as follows:

  • Pilot Light: Small gas flame serving as a source of ignition
  • Ignition Sensor: Electric ignition device that heats up furnace’s burners when necessary
  • Thermocouple: A kind of sensor detecting temperature and acting as a junction)
  • Gas Valve. (Controls flow of gas into the system)
  • Flame Sensor. (Safety device detecting heat from surface ignitor)
  • Pressure Switch. (Decides when to allow gas into the furnace)
  • Blower Motor. (Dissipates hot air created in the furnace through the vent into the building)

Now that you have the required knowledge and ideas, you should be able to fix your furnace with relative ease. This allows you the freedom to not rely on a technician and instantly cater to your heating needs. You may also save some money in the process.

If none of the steps mentioned seem to work, there might be a bigger problem with your furnace. In that case, consult a technician.

With these valuable insights, whenever your furnace won’t turn on, you’ll be able to tackle it like a pro!

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