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Common Furnace Problems

October 30, 2020

Since 2012, there has been an improvement in gas furnace technology, away from what we have always known. Traditional gas furnaces of the older generation normally have pilot lights and churn out non-condensed gases through chimneys. Newer and advanced versions churn their excess air through PVC pipes and often have an AFUE (annual fuel utilization efficiency) rating of 90% and above compared to the maximum of 89% of the older versions.

These improved versions are condensing and with a high heat efficiency. Since gas furnaces have been improved physically, with those improvements come a load of newer problems – different from what was obtainable. So today, we are going to see some common issues and steps of troubleshooting furnaces.

Issues and Troubleshooting Furnaces

Gas furnaces often work on these basic principles: accepting cold air,  purifying it with the air filter, heat the air up via a gas burner and heat exchanger (often made with steel),  and distributing the warm air through your home via the duct work. The warming and cooling technology are done in a repeated loop. The warm air flows through your home, and as it cools down, it returns into the gas furnace through the duct work and the filtration and heat pattern plus redistribution is replayed. Some designs of gas furnaces have humidifiers placed on the duct work.

Theoretically, the working process and even physical design of gas

furnaces are quite straightforward. However, there might be issues that would warrant gas furnace repair or a total furnace replacement. Whatever it is, you must be careful with troubleshooting gas furnaces and should call in a licensed professional. While there are issues you can fix yourself, beyond those, it isn't advisable. Let's get educated.

Gas Furnace Constantly Going On and Off

You know it is time to do a heater furnace repair when your gas furnace is often short cycling or constantly going on and off. A simple repair can save you lots of money and energy at a time. If the weather is considerably cold, short cycling might be considered a normal occurrence as the furnace tries to make your home comfortable. However, in moderate or warm weather, short cycling is an indication that there is a problem with your furnace – may be clogged, needs a filter replacement or has a bad thermostat.

Zero To Insufficient Heat

The essence of having a gas furnace is to make your home comfortable when the interior temperatures dip too low. However, when the furnace fails to produce heat, it is a strong indication that a maintenance repair is needed. If experienced, quick checks on the thermostat, the heat registers or the power availability in the furnace are some of the issues to assess first, but is still highly advisable to call an expert.

The Blower Runs Non-Stop

Furnace repair is needed if the blower runs nonstop. This can be caused by:

· A faulty fan control switch – this is easy, you may just have to reset or totally replace the control switch.

· The thermostat on fan setting – this might be useful or not, depending on what you need.

If your home is humid and stuffy, the constantly running blower can help dissipate the air or even filter it. However, the workload on the blower motor overtime can cause it to wear out prematurely. To fix this, set your furnace thermostat to auto so that the fan only runs when the system is cooling or warming - which is an efficient way to manage your energy consumption.

Annoying Sounds Coming from The Furnace

When your heater furnace makes annoying sounds like squealing, humming, or even a loud bang, know that it could become a serious problem if it continues to run that way. Furnace repairs and assessments should be done by professionals to prevent personal injury, and save time and money in the long run.  

However, the noises might be due to a clogged air filter or friction in the blower motor – which can be assessed by yourself, and a quick DIY project by replacing the air filter.

Pilot Light Goes Off

A dirty gas tube or pilot burner as well as a strong draft can cause the pilot lights of your gas furnace to go off.  Sometimes the fault may be from the thermocouple, which shuts off the gas supply. When this happens, your gas furnace might not produce heat to the property. This could be an easy fix, by relighting the heater or more advanced by replacing the thermocouple.

Wrong Thermostat In The Wrong Furnace

This issue is shockingly common. Installing the wrong thermostat on your home gas furnace can cause a lot of problems no matter the settings applied. Thermostats might be of low, milli, or line voltage, and installing the correct one should be a priority to avoid issues.

Bad Thermostat

Before checking for other causes of problems with your furnace, you must check the thermostat. A faulty thermostat can lead to a number of other problems and can be fixed easily too. Once your furnace air filter is fine and there is no noise coming from the system, it should work properly unless dealing with a faulty thermostat.  If everything else is fixed and your furnace still is not properly functioning, then you should call the pros to assess and find a solution.

Ignition Issues

Modern gas furnaces are equipped with electronic ignition. An electronic part ignited by electrical components turns on the gas pilot which in turn ignites the burners.  If there is a problem with the ignition system, your gas furnace will begin to malfunction. However, simple fixes like filter replacement, gas and power line checks, should do the trick. If it doesn’t, then you should call a technician.

In A Nutshell

Gas furnace troubleshooting should be done as early as you notice any irregular conditions with your furnace such as no heat, constantly running blowers, short cycling, or pilot lights that go off amongst others.

While some may be due to simple anomalies like a faulty thermostat or dirty filters (which of course you might be able to handle yourself), some might be much worse and would be risky if you do not call in a professional on time.

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