There are many important components to a furnace, but one of the most important is the limit switch. This component helps keep your furnace safe by shutting it down if it starts to overheat.
This part can be the difference between your furnace completely overheating, or shutting down safely, I have seen furnaces overheat during my time as a HVAC design engineer, believe me, you don’t want that to happen!
If you’re in the market for a new limit switch, or just want to learn more about them, then this is the guide for you! I’ll discuss what a limit switch is, how they work, and some of the best options on the market.
So read on to learn everything you need to know about limit switches and how to find the best furnace limit switches for your needs!
Bottom line: Furnace limit switches are an important part of any forced-air heating system, as they help to regulate and control the flow of electricity to the furnace. There are a variety of different types of furnace limit switches available on the market, so it is important to choose the right one for your needs. The Universal Parts SRL350_B Furnace Limit Switch L350F, L350 is a great option for most homeowners because it is easy to install and use, and it is compatible with a wide range of furnaces.
- Universal Parts SRL350_B Furnace Limit Switch L350F, L350 – Best Universal Option
- Goodman Amana 10123533 Limit Switch w/ Manual Reset – Best Budget Option
- Square D 9007C68T10 Side Rotary Spring Return Lever Limit Switch – Best Rotary Option
What is a Furnace Limit Switch?
A furnace limit switch is a safety device that is mounted on the side of the furnace. The purpose of this switch is to shut off the gas flow to the burner in the event that the temperature inside the furnace rises to unsafe levels.
This switch is usually located near the top of the furnace where it can monitor the temperature inside the unit. Limit switches are typically made from materials that can withstand high temperatures, such as brass or stainless steel.
There are two main types of furnace limit switches: manual reset and automatic reset. The manual reset switch must be manually reset after it has been tripped, while the automatic reset switch will automatically reset itself after cooling down.
The most common type of limit switch used in furnaces is a mechanical switch that contains a bi-metal element. This element is designed to bend when exposed to heat, which causes the switch to trip and turn off the gas flow. Some newer furnaces use electronic limit switches that contain a heat-sensitive sensor. These switches are more accurate than mechanical switches and can be reset after they trip.
Most furnaces will have both a primary and a secondary limit switch. The primary limit switch is the one that is most likely to trip first, and it will usually shut off the gas flow to the burner. The secondary limit switch is designed to provide an additional layer of safety and will usually shut off the power to the blower motor.
Checking your furnace limit switch regularly is an important part of maintaining your furnace. If you notice that your switch has tripped, reset it immediately and then call a qualified technician to check your furnace and make sure that everything is working properly.
Interesting Read: How to Find the Best Furnace Blowers.
How Do Furnace Limit Switches Work?
A furnace limit switch’s purpose is to shut off the gas supply to the furnace if the temperature gets too high. This prevents the furnace from over heating and becoming a fire hazard.
The limit switch consists of two parts, the sensing bulb and the switch itself. The sensing bulb is filled with a liquid that expands when heated. As the temperature inside the furnace rises, the liquid in the sensing bulb expands and pushes against a diaphragm inside the switch. This causes the switch to trip and open the circuit, shutting off the gas supply to the furnace.
Limit switches are an important safety feature of furnaces and should be tested regularly to ensure they are working properly.
Why Are Furnace Limit Switches Important?
There are a few key reasons why furnace limit switches are important:
- First, they act as a safety measure to prevent the furnace from over-heating. If the temperature inside the furnace gets too high, the limit switch will shut it off before any damage can be done.
- Second, limit switches can help improve the efficiency of your furnace. By preventing the furnace from running when it doesn’t need to, you can save money on your energy bills.
- Finally, limit switches can prolong the life of your furnace by preventing it from being overworked. When a furnace is overworked, it can wear out more quickly and eventually break down completely.
By using a limit switch, you can help to ensure that your furnace lasts for many years to come.
How To Install a Furnace Limit Switch
If your furnace is having problems starting up, or if it seems to be running for too long after reaching its target temperature, it could be an issue with the limit switch. In this article, we’ll show you how to install a new furnace limit switch. Before beginning any work on your furnace, make sure that it is turned off and disconnected from all power sources.
- Locate the old limit switch. This will usually be mounted on the side of the blower compartment, near the bottom of the unit.
- Disconnect the wires from the old switch. Be sure to note which wire is attached to which terminal, so that you can reconnect them correctly to the new switch.
- Remove the old switch from its mounting bracket, and discard it.
- Install the new limit switch in the same location as the old one, making sure that it is properly aligned with the mounting bracket.
- Reconnect the wires to their respective terminals on the new switch. Make sure that all connections are tight and secure.
- Replace the cover on the blower compartment, and secure it in place.
- Turn on the power to the furnace, and test the new switch by starting up the unit and letting it run for a few minutes. If everything is working properly, the limit switch will shut off the furnace if the blower fails to start, or if it runs for more than the set amount of time after reaching its target temperature.
Installing a new furnace limit switch is a fairly simple task that most homeowners can do themselves. However, if you are not comfortable working with electrical components, it is always best to hire a professional to handle the job. Improper installation of a furnace limit switch can lead to serious safety hazards.
Common Problems With Furnace Fan Limit Switches
If your furnace fan limit switch is having problems, it can cause a number of issues with your furnace. Let’s go over some of the most common problems that occur with furnace fan limit switches, as well as how to fix them.
One of the most common problems that occur with furnace fan limit switches is that they become clogged with dust and dirt. Over time, this can cause the switch to become less sensitive, which can lead to it not turning on or off when it should. If you notice that your furnace fan isn’t coming on when it should, or if it’s taking longer than usual to turn off, then you may need to clean your switch. To do this, simply disconnect the switch from the power source and use a brush or vacuum to remove any dirt or debris that may be blocking the switch.
Another common problem that can occur with furnace fan limit switches is that they become damaged. This can happen if the switch is hit by something, or if it’s exposed to extreme temperatures. If you notice that your switch isn’t working properly, or if it shows signs of physical damage, then you’ll need to replace it.
In some cases, furnace fan limit switches may simply go bad over time. If your switch is more than a few years old, then it’s likely that it will need to be replaced. However, if you’ve only had your furnace for a year or two, then a bad switch may just be a result of normal wear and tear.
If you’re having problems with your furnace fan limit switch, then there are a few things that you can do to try and fix the problem. First, you can clean the switch as described above. If this doesn’t work, then you may need to replace the switch. Finally, if all else fails, you can always contact a professional to have your furnace serviced.
Best Furnace Limit Switches On The Market
There are many different brands and models of furnace limit switches on the market, so it is important to do your research before purchasing one. Below I’ll take a look at some of the best furnace limit switches on the market and help you choose the right one for your needs.
The first thing you need to consider when choosing a furnace limit switch is what type of fuel your furnace uses. There are two main types of furnace limit switches: those for natural gas furnaces and those for oil furnaces. If you have a natural gas furnace, you’ll need to purchase a switch that is rated for use with natural gas. Similarly, if you have an oil furnace, you’ll need to purchase a switch that is rated for use with oil.
The next thing to consider is the climate in which you live. If you live in an area with a cold climate, you’ll want to choose a furnace limit switch that is designed to withstand low temperatures. Conversely, if you live in an area with a warm climate, you’ll want to choose a switch that is designed to withstand high temperatures.
Finally, you need to decide how many switches you need. The number of switches you need will depend on the size of your furnace and the complexity of your HVAC system. If you have a large furnace or a complex HVAC system, you may need more than one switch.
Once you’ve considered all of these factors, you’re ready to start shopping for a furnace limit switch. Below I’ve compiled a list of some of the best furnace limit switches on the market, so you can find the perfect one for your needs.
I’ve compiled a list of the best furnace limit switches on the market, based on a variety of selection criteria.
The first criterion I looked at was the operating temperature range. I only included switches on my list that are rated for use in environments with temperatures up to 200 degrees Fahrenheit. This ensures that they’ll be able to handle the heat produced by a furnace without any problems.
Another important criterion was the amperage rating. I only included switches on my list that are rated for up to 30 amps of current. This is more than enough to handle the current drawn by most furnaces.
Finally, I looked at the price of each switch. I wanted to make sure that my list included options for everyone, so I included a mix of high-end and budget-friendly switches.
Now that you know the criteria I used to select the best furnace limit switches on the market, let’s take a look at my top picks!
Universal Parts SRL350_B Furnace Limit Switch L350F, L350
If you’re in the market for a new furnace limit switch, the Universal Parts SRL350_B Furnace Limit Switch L350F, L350 is one of the best options available. Here’s why:
The Universal Parts SRL350_B is a top-of-the-line furnace limit switch that is designed to last. It features a durable metal construction and a robust design that can withstand years of use.
This furnace limit switch also has a great reputation for being easy to install. In most cases, it can be installed in just minutes with no special tools or skills required.
Once installed, the Universal Parts SRL350_B will provide you with reliable performance year after year. It features a precision-engineered sensing element that ensures accurate and consistent operation.
Plus, the Universal Parts SRL350_B comes with a full 1-year warranty, so you can be confident in its performance.
If you’re looking for a top-quality furnace limit switch that is built to last, the Universal Parts SRL350_B is a great option. It’s easy to install, reliable, and backed by a comprehensive warranty.
- Easy to install
- The switch may not be compatible with some furnaces
- The switch may not be suitable for very high-temperature applications
Goodman Amana 10123533 Limit Switch w/ Manual Reset
When it comes to choosing a limit switch for your furnace, there are a few things you need to take into account. The Goodman Amana 10123533 Limit Switch w/ Manual Reset is one of the best options on the market, and here’s why:
- First of all, this limit switch is designed for use with Goodman and Amana furnaces. It’s a perfect fit for those models, so you know it will work well.
- Second, the manual reset feature is a great addition. This means that if the switch trips, you can simply reset it without having to call a technician.
- Third, the quality of this limit switch is top-notch. It’s durable and reliable, so you can rest assured that it will last for years to come.
- Fourth, the price is very reasonable. Considering the quality of this switch, it’s a great deal.
- Finally, the Goodman Amana 10123533 Limit Switch w/ Manual Reset comes with a one-year warranty. This shows that the company stands behind its product and is confident in its quality.
Overall, the Goodman Amana 10123533 Limit Switch w/ Manual Reset is a great choice for anyone looking for a high-quality, affordable limit switch for their furnace. It’s durable, reliable, and easy to use, making it a great option for any home.
- The Goodman Amana limit switch is a high-quality product that is built to last.
- It features a manual reset, so you can easily reset the switch if it trips.
- This limit switch is compatible with all Goodman and Amana furnaces.
- Some customers have reported that the manual reset can be difficult to use.
- This limit switch is not compatible with all brands of furnaces.
Square D 9007C68T10 Side Rotary Spring Return Lever Limit Switch
If you’re in the market for a quality furnace limit switch, the Square D 9007C68T10 Side Rotary Spring Return Lever Limit Switch is definitely one to consider.
- It’s made by Square D, one of the most trusted names in electrical products.
- It’s incredibly durable and well-made, so you can rest assured it will stand up to repeated use.
- The side rotary spring return lever makes it easy to operate, even if you have limited space around your furnace.
- It’s easy to install and wire, making it a great option for both professionals and do-it-yourselfers alike.
- It comes with a one-year warranty, so you can be confident in your purchase.
If you’re looking for a top-quality furnace limit switch, the Square D 9007C68T10 Side Rotary Spring Return Lever Limit Switch is a great option to consider.
- The switch is designed for heavy duty applications and can handle a large amount of electrical current.
- The switch is very durable and can withstand constant use.
- The switch is easy to install and does not require any special tools or skills.
- The switch is very versatile and can be used in a variety of applications.
- The switch is extremely reliable and has a long lifespan.
- The switch is quite expensive compared to other similar products on the market.
- The switch is not suitable for use in all applications due to its specialized design.
- The switch requires regular maintenance and cleaning to ensure optimal performance.
Rheem Limit Switch – Auto Reset
The Rheem Limit Switch – Auto Reset is one of the best furnace limit switches available. Here’s why:
- First and foremost, the Rheem Limit Switch – Auto Reset is designed to automatically reset itself if it trips. That means that if your furnace goes on and off due to temperature fluctuations, you won’t have to constantly reset the switch yourself – it’ll take care of itself.
- Another big selling point of the Rheem Limit Switch – Auto Reset is its durability. This switch is built to last, with a heavy-duty construction that can withstand years of repeated use. Plus, it comes with a 5-year warranty, so you can be confident that it will stand up to the test of time.
- Finally, the Rheem Limit Switch – Auto Reset is very easy to install. It’s a simple matter of attaching the switch to your furnace’s control panel, and you’re good to go. No special tools or knowledge are required, so anyone can do it.
If you’re looking for a top-quality furnace limit switch, the Rheem Limit Switch – Auto Reset is a great option to consider. It’s well-made, durable, and easy to use, making it a great choice for both new and experienced furnace owners alike.
- It is easy to install and does not require any special tools or skills.
- It is compatible with most models of furnaces and air conditioners.
- It has a built-in safety feature that prevents it from overheating.
- It is backed by a 1-year warranty.
- Some users have reported that the Rheem limit switch can be difficult to adjust.
- It may not be compatible with all models of furnaces and air conditioners.
Question: What can happen if a furnace limit switch is not working properly?
Answer: If your furnace limit switch is not working properly, it could lead to a number of problems. The most serious problem is that it could cause your furnace to overheat and shut down. This could damage your furnace and create a fire hazard.
Another problem that can occur if your furnace limit switch is not working properly is that your furnace may not provide enough heat to keep your home warm. This could be a major issue during the winter months when you need heat the most.
If you notice that your furnace is not providing enough heat or if it shuts down frequently, you should contact a qualified repair technician to check the limit switch and make any necessary repairs. Ignoring this problem could put you and your family at risk.
Question: How can I tell if my furnace limit switch needs to be replaced?
Answer: If your furnace limit switch needs to be replaced, it is probably because it has failed to do its job properly and has allowed the furnace to overheat.
• There are several signs that your furnace limit switch may need to be replaced, including:
• The furnace shutting off unexpectedly or cycling on and off more frequently than usual
• The furnace is not reaching the set temperature
• The flame sensor is not working properly (Read: How to Find the Best Replacement Flame Sensors?)
• If you notice either of these issues, it is important to have a professional technician take a look at your furnace. They will be able to diagnose the problem and replace the limit switch if necessary.
Question: How can I troubleshoot my furnace limit switch problem?
Answer: If your furnace limit switch is not working properly, it could be caused by a number of different things. Here are some tips on how to troubleshoot your furnace limit switch problem:
• Check the wiring to the limit switch. Make sure that all of the connections are tight and there are no loose wires.
• Check to see if the switch is tripped. If it is, simply reset it and see if that fixes the issue.
• Clean the contacts on the limit switch. Occasionally, the contacts can become dirty or corroded, which can prevent the switch from working properly.
• Check to see if there is power going to the switch. If there is no power, then you will need to replace the switch.
• Replace the limit switch. If none of the above solutions fix the problem, then you may need to replace the limit switch. This is a relatively easy task that any qualified HVAC technician can do.
Question: Where can I find a replacement furnace limit switch?
Answer: There are a few places you can check when you need to find a replacement furnace limit switch. Your first option is to contact the manufacturer of your furnace and see if they sell replacement parts. If they don’t, then you can try searching for the part online. There are a few different websites that sell furnace parts, so you should be able to find what you’re looking for. Finally, if you can’t find the part anywhere, then you can always try contacting a heating and cooling contractor. They may be able to help you find the part or even install it for you.
When you’re searching for a replacement limit switch, be sure to pay attention to the specifications of the part. Make sure it is compatible with your furnace model and that it has the same voltage rating. Installing a new limit switch is a fairly simple process, but it’s always best to consult your furnace’s owner’s manual before beginning any repair.
Question: How much does it cost to install a furnace limit switch?
Answer: The cost of installing a furnace limit switch will vary depending on the type of furnace you have, as well as the size and model of the switch itself. Generally speaking, however, you can expect to pay anywhere from $50 to $200 for professional installation, plus the price of the unit itself.
If you are handy with tools and comfortable working around electricity, you may be able to install the switch yourself; however, it is always best to consult with a qualified HVAC technician before attempting any work on your own.
Choosing the best furnace limit switch will ensure the safe and efficient operation of your furnace. By understanding how these switches work and what factors to consider when choosing one, you can make an informed decision that will keep your furnace running smoothly for years to come.
Thanks for reading, I hope this guide was helpful!