Why Isn’t My Furnace Working?

by | Nov 10, 2017 | Blog, Heating | 0 comments

How to identify problems with your furnaceIt’s Winter, and even with this year’s mild winter, we’ve already had a few cold snaps and freezing temperatures.  If your furnace stops in the middle of winter, you don’t want it to stay down for very long.  Especially if it’s something that you can take care of yourself.  There are two very basic types of problems with a furnace.  The first is that it won’t turn on at all, and the second is that it won’t function properly when it is on.  Whether you want to call them signs or problems, today we have the 3 most common ways for you to tell that something has gone wrong.

Furnace Start Failure

According to this website, The single most obvious problem with a furnace is that won’t even turn on.  Whether you fail to hear the fan kick in, the sound of energy running to the blower motor, the noise of gas to the furnace, or the roar of flames from the furnace itself, a dead furnace is just that: dead.  Unfortunately, a non-functional furnace can be caused by any of a large number of failure points.  Common problems come from the thermostat, feeds lines, circuit breaker, and pilot light.

The first thing you should check is power.  Examine your circuit breaker box and make sure the circuit labeled for heating hasn’t been tripped.  If it has, reset it and wait to see if it re-trips or the furnace engages.  You should also check to see if your furnace has an emergency cut-off switch at the furnace.  Make sure that isn’t turned off.

Check your thermostat first if the heater isn't workingSecond: check the thermostat.  Is it set properly?  Is it correctly reading the room temperature?  If the answer is yes to both questions the thermostat may be broken.  It could be a switch issue or it could simply be failing to send a control signal to your furnace.  Either way, it should be replaced.  If the thermostat is working and you’re simply receiving cold air, then you likely have a furnace heat problem.

Finally, check the pilot light and fuel source.  If you have an electric furnace there could be a problem with the heating element.  If you’re getting cold air, it’s because there’s nothing to heat it.

Breaker Trips

Your furnace should be the only item on its breaker circuit.  This means any problems with the breaker are with the heating system or the breaker itself.  More than likely the furnace blower fan motor is overdrawing because it’s overworked.  When this happens, the power draw increases, heating up the breaker and causing a trip.

There are three possible causes for an overworked fan motor.  The furnace filter is dirty and causing an air blockage, the ventilation ducts need to be cleaned, or the motor itself needs to be maintained.  If you had a proper maintenance done on the furnace it’s likely that the ventilation ducts are simply too dirty to push air out into the house effectively.  Otherwise, we’d advise having an electrician check the wiring and breaker panel for faults.

Furnace Fan Activates with Cold Air

Sometimes you’ll find that the fan kicks in but the vent only seems to deliver cold air.  This first thing you should do is make sure that your thermostat is set to “Auto” rather than “Fan.”  This is a common mistake and it’s easily fixed.  The Fan setting leaves the blower fan running to circulate the air, but it does not activate the furnace heating.

Other reasons involve furnace fuel.  If you can, check the pilot light to make sure it’s on.  If you hear the sound of fuel but don’t see a pilot light, shut down your furnace and call a technician immediately.  If the pilot light is active but you still aren’t getting heat, check your fuel level.

Problems with the pilot light and fuel systems should be worked on by a professional.  If you use an electric furnace that isn’t heating, you’ll need to consult a furnace electrician.  Electric furnaces require a great deal of power for heating, creating dangerous conditions for the untrained.

Of course, there are other signs you should be on the lookout for.  Strange smells or sounds when the furnace is running can hint at further problems.  If your furnace itself is beeping or making noise, then it definitely needs your attention.  While we always hope that nothing will go wrong, it’s nice to know the causes of these common problems and when we can fix them.


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