How does a gas furnace ignition system work?
The ignition system has a safety mechanism that observes the pilot for up to five seconds to ensure that it’s burning normally. If everything is fine, it allows gas to flow to the burners. Then the pilot lights the burners, and your furnace comes on.
How do you light a gas furnace with electronic ignition?
To light a gas furnace with electronic ignition, start by turning the furnace’s thermostat to its lowest setting. Cut off the power to the furnace next then turn the igniter off and wait for the gas to clear. After waiting, you can switch the igniter back on, bring the power back, and watch the pilot light come alive.
Where does the igniter go on a gas furnace?
The igniter is positioned in the flow of gas entering the burners. When the thermostat calls for heat, 24 volts are sent to the electronic ignition control module, which energizes the furnace blower and other systems and sends 120 volts to the HSI.
What is intermittent pilot ignition on a gas furnace?
Intermittent pilot ignition systems are solid-state ignition devices that automatically light a pilot burner. They also energize the heating system’s main gas valve when the thermostat calls for heating. Intermittent ignition systems use a spark plug that produces a spark to light the furnace’s burners.
How does electronic ignition work on a furnace?
When electrical current flows through it, the metal gets hot enough to ignite the furnace burners. The current only flows through the metal when the thermostat triggers a heating cycle. Hot surface igniters are the most common type of electronic ignition.
Does a furnace with electronic ignition have a pilot light?
Newer gas furnaces (since about 2010) do not have a traditional pilot light that burns all the time. Instead they use electronic ignition systems that light only as needed.
How does electronic ignition work?
An electronic ignition system is a type of ignition system that works electronic circuits, usually by transistors. The transistors are controlled by sensors to generate electric pulses which then generate a high voltage spark that can burn the lean mixture and provide a better economy and lower emission.
How do you test an electrical igniter on a furnace?
1:062:01Furnace Not Igniting or Heating? Igniter Testing, Repair - YouTubeYouTubeStart of suggested clipEnd of suggested clipUsing a digital model again rotate the dial to the lowest setting for ohms of resistance orMoreUsing a digital model again rotate the dial to the lowest setting for ohms of resistance or resistance with tone if your meter has this option to test the igniter shut off the power to your furnace.
Is electronic ignition better than pilot light?
Since a standing pilot requires constant fuel, an electronic ignition is considerably more cost-efficient. This is because between electronic ignition vs. standing pilot, there would be little to no waste of gas for the first one as it shuts off as soon as the burners ignite.
How do I reset my electronic ignition furnace?
How to Reset an Electric FurnaceFirst, turn off the power supply to the furnace by turning off the breaker in the circuit box.Locate the reset button on the furnace and press it to reset the furnace. ... If the button is popped up, press it down.Return the cover to the blower compartment and turn the power on.
What are the disadvantages of electronic ignition systems?
The main disadvantage of electronic Ignition is that this system is very expensive because all cannot afford the vehicles having an electronic ignition system.
Does electronic ignition need electricity?
Newer generations of gas fireplaces and appliances use an electronic ignition system. This does require electricity to start up.
How do you bypass an electronic ignition switch?
Connect the positive terminal of the battery to the positive side of the ignition coil. Also, identify the starter solenoid and connect it to the positive terminal of the battery. Next, unplug the ignition switch wire from the solenoid and then short the solenoid's terminal to reach where the ignition switch connects.
Can you manually light a gas furnace with electronic ignition?
If your furnace is equipped with an electronic igniter, you cannot light the furnace manually. However, you may be able to get the furnace working by turning off the igniter and resetting it. Find the paperwork for your particular furnace to locate the reset button or switch.
Why is my furnace running but not igniting?
If your gas furnace initiates the start cycle but does not fire up, it's likely because of a faulty, damaged, or dirty ignitor/sensor. This is a very common furnace problem—you can try to clean the sensor and replace the ignitor.
What are the symptoms of a bad furnace ignitor?
Here are a few indications that you have a faulty ignitor.No Cold Air. ... The Furnace Won't Come On. ... The Furnace Suddenly Stops Blowing. ... Starts, Then Stops, Then Starts Again. ... Tripping the Breaker More Than Once. ... I Hear the Click, But Nothing Happens. ... Flame Sensor Problems. ... Short Circuit.More items...•
Does a furnace with electronic ignition have a thermocouple?
Electronic ignition gas systems do not use a thermocouple or thermopile to prove the flame. Electronic ignition gas ignition systems use a flame sensor that measures microamps to prove the flame.
Does auto ignition require a pilot flame?
Differences of an automatic ignition compared to a manual ignition of a gas stove range: Electricity is needed – an automatic gas stove ignition needs electricity to ignite gas in a stove, while a manual gas stove ignition will require a match, a lighter, or a pilot light to start a fire.
How do I light my electronic pilot light?
Turn the valve to the “pilot” position. Press and hold the reset button. If the reset button fails, ignite the lighter. Hold down the reset button and bring a grill lighter or long match to the pilot light valve until the pilot ignites.
How do I relight my electric pilot?
Relight the pilot light. Turn the knob to “Pilot,” and let gas to flow to the pilot. Light a lighter or match, then push in the reset button. Hold your flame to the pilot light's opening. Keep the reset switch depressed until the pilot light is burning steadily.
Why do gas furnaces use standing pilot lights?
However, because standing pilot lights consume extra power to stay lit, they reduce furnace efficiency. The new electric ignition systems require only a small amount of electricity and do run continually. This is one of the reasons that new furnaces have higher efficiency ratings.
Why do you need a gas furnace in DC?
If you installed a gas furnace for your heating in Washington, DC, instead of an electric one, it was probably because of the savings you receive using natural gas, a more economical power source than electricity. However, if you have a modern gas furnace, it still needs a small amount of electricity to run. The key electrical system in a gas furnace is the electric ignition, which we’ll examine in detail.
Is it safe to use gas furnaces?
Gas furnaces are safer today than ever before, and it is partially thanks to electric igniters. But don’t let your furnace go without yearly maintenance: keeping those igniters working their best is how you know your furnace is working its best. Contact Polar Bear Air Conditioning & Heating Inc. to sign up for our maintenance program for your heating in Washington, DC.
Does a furnace intermittent pilot work?
Furnace intermittent pilots – This system does use a pilot light; however, the pilot light comes on only when needed and an electric spark activates it. When the thermostat calls for heat, high voltage sent through the igniter causes a spark that ignites the pilot, and it supplies sufficient heat to turn on the burners. The pilot light shuts off when the burners do.
Where to buy a furnace ignitor?
If you or a qualified technician determine the furnace ignitor is the culprit, then you can pick one up from a local hardware store. Your furnace manual includes information on the correct model to buy. You can also check with your retailer, who can look up that information.
What temperature does a furnace ignitor go to?
The ignitor sits beside the gas burners, and when the thermostat communicates that it’s time to distribute warm air, the hot surface ignitor can reach 2500 degrees Fahrenheit.
How to tell if the furnace ignitor is bad?
Before diagnosing the gas furnace ignitor as the source, check your thermostat to ensure you have the setting switched to heat. If so, then the ignitor isn’t creating the combustion needed to warm the air.
Why does my furnace ignitor stop working?
Another reason your ignitor quits working is it receives too much power. If you notice your breaker box trips every time your furnace turns on, it means your ignitor cannot handle the power load. Find a local electrician to inspect and repair the problem.
Why does my furnace not start?
If you hear the furnace click on but it never fully fires up to begin the heating cycle, a faulty furnace ignitor is likely to blame. In this situation, the furnace detects there’s a problem (often with the ignitor’s inability to create a combustion) and shuts down to keep you safe. Call your local furnace technician to perform a furnace ignitor replacement.
Why does my furnace keep turning on and off?
When this happens, the furnace detects something is wrong, and as a safety measure, shuts it off.
Why does my furnace make a clicking noise?
When you turn up the thermostat to initiate your furnace, you might notice a clicking sound before the warm air arrives. That noise comes from the furnace ignitor.
How to ignite a thermostat?
Turn the thermostat to your preferred temperature as well and wait for the pilot light to go on. Hopefully, the pilot light will indeed ignite and the burners will follow.
How much does it cost to replace a furnace igniter?
Different components of a gas furnace with electronic ignition will have to be replaced as they age. Those include the blower motor, the flame sensing rod, and of course, the igniter. So, how much will you have to pay to replace the igniter? A replacement igniter itself is very affordable. You can find parts that are available for as low as $20 and even the pricier options top out at $40.
What Are the Issues That Could Affect an Intermittent Pilot Light?
Two of them stand out for being fairly common. The first issue typically involves the electronic spark triggering but nothing happening after that. That spark is supposed to give life to the intermittent pilot light. For one reason or another though, there are times when it may fail to do its job.
What Should I Do if the Pilot Light Still Fails to Ignite?
Let’s say that you followed the steps above but after moving the thermostat, you’re still not getting heat. Upon closer inspection, you also noticed that the pilot light did not ignite.
Why does my gas furnace have a blue flame?
There are times however when that blue flame will go out. It may go out due to a draft close to the furnace or dirt buildup.
What is a pilot light in a furnace?
Gas furnaces rely on small flames to provide the heat homeowners are calling for. That small flame is known as the pilot light. The pilot light’s job is to ignite the gas coming from the main burner. After all, you cannot just stick a match in there. You have to rely on the pilot light to essentially allow the furnace to do its job.
Why is my furnace not working?
The furnace inside your home may not be able to do its job if its air filters are dirty. Check on those air filters while inspecting your gas furnace. They could very well be the reasons why the gas furnace is not working properly so clean them if necessary.
How Do Electronic Ignition Systems Work?
Electronic ignition systems come in two main types – intermittent pilot systems and hot surface ignition systems.
Why does ignition happen?
The ignition happens because the spark discharge activates the fuel particles between the two electrodes, triggering an oxidation process (chemical reaction in which an atom or compound loses one or more electrons).
Why does the pilot ignition system shut off the gas valve?
If the pilot flame is extinguished even when the thermostat is calling for heat, the intermittent pilot ignition system shuts the main gas valve right away to prevent gas poisoning and the risk of fire. The ignition will produce another spark about 0.8 seconds later to attempt to relight the pilot. If everything goes well this time, the furnace enters a heating cycle.
What is an intermittent ignition system?
Intermittent ignition systems use a spark plug that produces a spark to light the furnace’s burners. When your thermostat calls for heat, the furnace’s circuitry passes a high voltage between the spark plug’s center electrode and ground electrode, breaking down the insulation between the electrodes and allowing current to flow in the discharge phenomenon.
How long does it take for a furnace to turn red?
This way, it takes only a few seconds, typically less than five, for the ignitor piece to glow red hot. Once it’s at least 2500°F hot, the ignitor requests the furnace to open the main valve to allow gas to flow to the pilot system.
How long does it take for a fire ignitor to glow?
The ignitor glows red hot: This typically takes up to five seconds, depending on the type of hot surface ignitor.
What is electronic ignition?
The term “electronic ignition” refers to ignition systems that rely on an electrical switch to initiate heating. Instead of a standing pilot system that stays on throughout, electronic ignition systems use transistors controlled by sensors to generate electronic pulses that ultimately ignite the flame. As a result, the electronic ignition system doesn’t need to stay on continuously.
What is an electronic ignition system?
The electronic ignition system in a gas furnace is a modern development that provides more reliable performance than a standing pilot system, offering energy savings through better furnace efficiency. There are two basic types of electronic ignition systems:
How does an induced draft furnace work?
Induced draft furnaces use a small fan to draw the combustion gases from the combustion chamber and out of the house through the flue (chimney). This system is more reliable and safer than old conventional furnaces, which relied on a natural draft coming in from an opening at the front of the furnace. Induced draft furnaces use either an intermittent pilot (IP) or hot surface ignition (HSI) instead of a standing pilot light. The combination of electronic ignition, electronic controls, and artificially created draft improves the efficiency of induced draft furnaces over older conventional models.
How does a furnace HSI work?
When the thermostat calls for heat, 24 volts are sent to the electronic ignition control module, which energizes the furnace blower and other systems and sends 120 volts to the HSI. The HSI heats up to around 1,800 to 2,500 degrees Fahrenheit and glows red-hot. Then the gas valve opens, and the burner gas is ignited by the HSI. Once a proper flame is sensed by the flame sensor, the HSI turns off and stays off until the next heating cycle. In some furnaces, the HSI also serves as a flame sensor (called local sensing) instead of having a separate sensing rod in the burner flame (remote sensing).
What are the problems with IP ignition?
Common problems with IP ignition include: Ignition doesn't occur, and the furnace won't go on. A spark is present, but the pilot won't light. Pilot lights, but the main burner doesn't come on. Burners ignite but turn off after a few seconds. Michael Interisano / Design Pics / Getty Images.
How many volts does a furnace blower use?
When the thermostat calls for heat, 24 volts are sent to the electronic ignition control module, which energizes the furnace blower and other systems and sends 120 volts to the HSI. The HSI heats up to around 1,800 to 2,500 degrees Fahrenheit and glows red-hot.
How many heat exchangers does a condensing furnace use?
Condensing furnaces use two heat exchangers, where conventional furnaces use only one. After the gas is burned to heat the primary heat exchanger, the secondary heat exchanger draws heat out of the hot exhaust gases, cooling them to the point that the water vapor in the exhaust condenses into water.
What is the purpose of understanding the basic components of a furnace?
Understanding some of the basic components of a modern furnace will help you identify the type of furnace you have and narrow down the list of potential problems .
Furnace not igniting because of incorrect thermostat setting
Many homeowners forget they need to change their thermostat setting back to ‘heat’ or ‘heating’ after a mild fall. An accidental change or power outage could also mean you need to reset your thermostat to your preferred setting. Before we get into more difficult fixes, check your thermostat.
Furnace not igniting burners due to tripped circuit breaker or blown fuse
It is possible a tripped circuit breaker or blown fuse may be the underlying reason your furnace is not igniting properly. Though this may seem like too simple a problem, rule it out before proceeding.
Gas furnace will not ignite because of a faulty gas line
A faulty gas line could be the reason your gas furnace is not lighting. First, check and make sure that your gas is turned on. Your shut-off valve should be outside and will resemble a rubberized strip of metal about five inches long. If it is perpendicular to the gas pipe then it is turned off. If it is parallel with the gas pipe, it should be on.
Gas or oil furnace not igniting because of dirty burners
Dirt or grime on the burners themselves can restrict the flow of air and prevent the burners from lighting. If the burners look dirty, you can try cleaning them to get them to ignite.
Furnace maintenance tips
To ensure your furnace runs smoothly when you need it to, follow these maintenance steps throughout the year.
How to know if you need a repair vs replacement?
A professional HVAC technician will tell you if it is time to replace your furnace system. Some tell-tale signs, however, include:
Is this something I can fix myself?
It depends on your comfort level removing burners and replacing electronic ignitions. If that is something you are comfortable with, you may be able to fix it yourself. In many cases repairing a furnace is a job better suited for a licensed professional so that you know it is being done right.
