Circuit breakers are an essential safety feature that helps to prevent fire hazards and electrical damage that could occur if the circuit is overloaded. If the circuit does ever overload, the breaker will automatically trip to ensure that the wires can’t overheat and melt or start a fire. Although a gas furnace doesn’t draw all that much electricity, it may still overload its circuit and trip the breaker if the heating system is working too hard or has any electrical issues. If you do ever find that your furnace has tripped the circuit breaker, here are the potential reasons why it happened and what can be done about them.

1. Clogged Air Filter

The main reason that a furnace will trip the circuit breaker is that the blower fan is working much harder due to restricted airflow, and this usually happens because the air filter is clogged. When the air filter is overly dirty and clogged, very little air can flow through it. This puts a huge amount of extra strain on the blower as it needs to work harder to draw air in through the filter. When the blower is forced to work harder, it will often draw more power and potentially overload the circuit, causing the breaker to trip automatically.

The only way to ensure that this issue doesn’t happen is to check your filter regularly and replace it at least every 30 to 90 days. The easiest way to know if your filter needs to be replaced is to hold it up to a light. If you can easily see some light through the filter, it means it is still in good condition. If you can’t see any light through it or the filter looks black, you’ll want to replace it as soon as possible.

It is also important that you use the right type of filter for your HVAC system. If you use too efficient of a filter, it will also seriously restrict the airflow and lead to the same issue.

2. Closed or Blocked Vents

If your furnace ever trips the circuit breaker, you will also want to check all of your supply and return air vents in addition to the air filter. Specifically, you will want to make sure that all of the vents are open, not clogged with hair and debris and not blocked by furniture or other items. Closed or obstructed vents will also restrict how much air can flow through your HVAC system by increasing the airflow resistance inside of the ductwork, and this will also put extra strain on the blower and potentially cause it to overload the circuit and trip the breaker.

The best way to avoid this issue is to always leave all of your vents open. It is normally fine to close one or two vents if you have rooms that you never use and don’t need to heat. However, you should never close more than 25% of your vents, or the airflow resistance will be much higher, and the blower fan will struggle to circulate air properly.

3. Air Duct Leaks

Any air leaks in your duct system will also make it harder for the blower fan to circulate air and potentially cause it to overload the circuit. This is why you should always have your ductwork inspected every year or two to ensure it is in good condition and not sagging or damaged. If your ductwork is more than 10 years old, it is usually a good idea to have it resealed to ensure there are no leaks. If your ductwork is 20 or more years old, it’s probably time to start thinking about having it replaced. Ductwork typically has a maximum life span of around 25 years and will generally start to deteriorate and suffer from more leaks the older it gets.

4. Short or Ground Fault in Furnace or Blower

An overloaded blower isn’t the only reason that your heating system can trip the circuit breaker. It can also happen due to a short or ground fault caused by damaged wiring in the furnace or the blower. A short circuit occurs when an exposed bare wire comes into contact with a neutral wire, whereas a ground fault happens due to an exposed wire contacting the ground wire or anything metal. Both shorts and ground faults will cause a huge amount of excess current to flow, leading to the circuit overloading and thus tripping the breaker.

Shorts and ground faults can result from the insulation or coating that surrounds the wires starting to decay due to age. The wiring can also be damaged due to the furnace overheating and causing the insulation to begin to melt.

If your furnace continually trips the circuit breaker, it most likely indicates that there is an electrical issue with the furnace or blower motor. In this situation, you will want to have your heating system inspected as soon as possible. This is because continually overloading the circuit could lead to a risk of fire or seriously damage your electrical system or your furnace.

5. Malfunctioning Breaker or Electrical Panel

There is also the possibility that the problem is related to your electrical panel or the circuit itself and has nothing to do with your furnace. It could be that the panel or the breaker is damaged or faulty or that the breaker connection is loose. If an HVAC technician determines that your furnace and blower are working properly, you will then want to have a licensed electrician inspect your electrical panel and possibly replace the breaker or the panel itself.

One sure sign that the issue lies with your electrical system is if you frequently experience power surges or issues with other circuits in your home as well. Visible rust on the breaker or panel is also a sign that you need to replace the panel. If your electrical panel is more than 25 years old, then a tripped circuit breaker also likely indicates that the issue is related to your electrical system and not your furnace.

6. Furnace Isn’t on a Dedicated Circuit

A furnace requires its own dedicated circuit that provides power to only it and the blower fan, and this is a requirement set out in the Canadian Electrical Code. If the furnace is on a circuit that is shared with other things, it will often end up overloading the circuit and tripping the breaker whenever the furnace or anything else draws power at the same time.

As long as your furnace was installed by a certified HVAC company, it will definitely be on its own circuit as all new furnace installations generally always require a permit and inspection. Nonetheless, it isn’t uncommon for HVAC technicians to occasionally encounter situations where a furnace is on a circuit that is shared with other things. If your furnace isn’t on its own dedicated circuit, you should have a licensed electrician rewire the system as soon as possible. This will prevent potential safety hazards and hopefully ensure that the breaker no longer trips.

If your furnace keeps tripping the circuit breaker or has any other issues, you can trust the experts at Western Pacific Heating, Cooling & Airflow for all of your repair needs. We repair and service all brands and types of furnaces and can quickly determine what the problem is and how to fix it. If your furnace is nearing the end of its life, we can also help you choose which new unit is best and ensure that it is installed properly and according to code. We also offer a full range of cooling, air purification and water heater services and specialize in designing and installing new HVAC systems for residential and commercial construction projects. Give Western Pacific Heating, Cooling & Airflow a call today to schedule a furnace inspection or if you need any other HVAC service in the Vancouver BC area.

Western Pacific Heating, Cooling & Airflow

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