What is the purpose of the ignitor on a gas furnace?
When the thermostat kicks on to start the furnace, the ignitor creates a spark that "ignites" the gas connected to your heater. Other types of ignitors heat without a spark. Instead, these ignitors heat up and touch the surface of the gas to heat the air blowing from the furnace.
What is intermittent ignition on a gas furnace?
This type of ignition system is durable and will not burn out. It lights the main burners, rather than a pilot burner. The intermittent pilot was the most common furnace ignition system in the second half of the 1900s. It used an automatic spark ignitor to light the main burners via a gas pilot light that was always on.
How does the hot surface igniter work on a gas stove?
As soon as the control board verifies all safeties are good and the pressure switch is closed, it engages the hot surface igniter by energizing it with voltage There is a slight delay allowing the hot surface igniter to reach temperature. The hot surface igniter will glow red hot. The gas valve will open feeding the burners with raw un-ignited gas.
What type of ignition system does my gas furnace have?
If you have a gas furnace in your home, the type of ignition system it employs will depend mainly on its age as well as the manufacturer who produced it. Here are the most common ignition systems found in home heating systems . If your furnace was manufactured within the last 20 years it will most likely have a hot surface ignition system.
How does a furnace spark ignitor work?
Furnace ignitor not glowing 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. The gas valve then opens, and gas is ignited by the burning ignitor. The ignitor will burn out over time.
What causes a ignitor to fail?
As mentioned above, sometimes the cause of a furnace ignitor failing to ignite is due to a safety issue, such as a clogged air filter, for instance. Air filters should be changed on a regular basis, to prevent these kinds of problems. However, a lot of furnace owners fail to do this.
Will a bad furnace ignitor still glow?
On most furnaces the ignitor will not glow unless all the safety controls (limit, rollout switch/switches, pressure switch) are closed. If a limit or rollout switch is open, you can have an overheating problem and a possible dangerous condition. You may need to replace the limit switch or rollout switch. 5.
What would cause a furnace not to ignite?
If your furnace won't ignite, the source of the issue may be a broken flame sensor. The sensor is responsible for turning off the gas burners to avoid gas buildup. Once this component starts to malfunction, it may stop the burners from igniting altogether.
How do you know if furnace ignitor is bad?
If you have a faulty furnace ignitor, it won't produce that tiny spark to heat the air coming from your Furnace. Your heater blows air at the same temperature as the cold outside air without it. Cold air blowing through your vents is a good sign that you have a heating problem within the Furnace.
Can a furnace ignitor be cleaned?
If your furnace has a spark ignitor and it's working haphazardly, it too could be covered with soot, and a blast of compressed air may be enough to clean it. Compressed air can also clean a blocked pilot tube that is causing the pilot flame to burn weakly or not at all.
How much does it cost to have a furnace ignitor replace?
Here's the bottom line: Whether for a natural gas furnace, oil, or a propane furnace, replacing a furnace ignitor–including parts and labor–will cost you around $300 – $425 for a qualified contractor to install. Compare that to, say, a draft inducer motor, which will cost $400 – $1,500 to replace.
How do I clean my furnace ignitor sensor?
1:053:46Furnace Cycling On and Off - Flame Sensor Cleaning - YouTubeYouTubeStart of suggested clipEnd of suggested clipSo if you have a situation like this what you have 90% of the time is just a dirty flame sensor. SoMoreSo if you have a situation like this what you have 90% of the time is just a dirty flame sensor. So we'll go through the steps on how to clean it. So the right side of the furnace.
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 no heat?
Dirty filters are the most common cause of furnace problems. Dust and dirt restrict airflow—and if the filter gets too clogged, the heat exchanger will overheat and shut off too quickly, and your house won't warm up. If the blower is running but no heat is coming out, replace the filter.
How long should it take for a furnace to ignite?
A furnace should take around five minutes to start once you've turned on your thermostat. That said, you might end up waiting closer to ten minutes to see your furnace kick on if it's older or has an issue with its pilot light. If this is the case, it may need to be checked out by a professional.
Why is my furnace clicking but not turning on?
Furnace Clicking, But Not Turning On – Flame Sensor The thermocouple is likely reacting to an abnormal flame temperature and shutting off the gas automatically. This is why the clicking sound continues. If you furnace begins clicking and the blower turns on and off again, this may indicate a faulty flame sensor.
Why do hot surface ignitors go bad?
Most of the time when ignitors go bad that often it is because the ignitor is not shutting off after the gas in the furnace is ignited. If the ignitor stays on for an extended period of time this will make the ignitor short-lived.
How much does it cost to have a furnace ignitor replace?
Here's the bottom line: Whether for a natural gas furnace, oil, or a propane furnace, replacing a furnace ignitor–including parts and labor–will cost you around $300 – $425 for a qualified contractor to install. Compare that to, say, a draft inducer motor, which will cost $400 – $1,500 to replace.
How much does an igniter for a furnace cost?
A furnace ignitor replacement costs $100 to $250 on average. Most universal hot-surface ignitor prices are $15 to $35 for the part alone. Gas furnace ignitor prices are $20 to $100 for parts from the original manufacturer (OEM). The labor cost to replace a heater ignitor is $80 to $200.
How do you test a spark igniter?
1:052:23Lennox # 73K38 - Continuity Test (Gas Furnace Ignitor) - YouTubeYouTubeStart of suggested clipEnd of suggested clipAlso set the dial to the lowest ohms of resistance to test for continuity take the probe from theMoreAlso set the dial to the lowest ohms of resistance to test for continuity take the probe from the multimeter. And touch it to one of the terminals. Now touch the second probe to the remaining.
What is intermittent pilot ignition?
Intermittent Pilot Ignition. The intermittent pilot was the most common furnace ignition system in the second half of the 1900s. It used an automatic spark ignitor to light the main burners via a gas pilot light that was always on.
What is Hsi in furnace?
Hot Surface Ignition (HSI) If your furnace was manufactured within the last 20 years it will most likely have a hot surface ignition system. Unlike older pilot light ignition systems, this type of ignition system reduces fuel waste by only burning fuel when the furnace is running. They are also quieter than pilot light or direct spark systems which ...
Does a rheem furnace have direct spark ignition?
Today, if you have a Ruud or Rheem furnace, chances are it will have a direct spark ignition. This type of ignition system is durable and will not burn out. It lights the main burners, rather than a pilot burner.
How long does a furnace ignitor last?
Fortunately, you can replace the ignitor without replacing the full furnace. Most ignitors last about seven years. Keep reading to learn how you can tell if your furnace problem is a faulty ignitor.
What happens if the furnace breaker is on?
If the furnace breaker is "on," there could be an issue with the ignitor, or you could have a more significant electrical issue.
What does it mean when your furnace starts clicking?
You've probably heard the "click" from your furnace before the air starts blowing. When the thermostat kicks on to start the furnace, the ignitor creates a spark that "ignites" the gas connected to your heater. Other types of ignitors heat without a spark.
How to know if furnace is out?
The Warning Signs of a Faulty Furnace Ignitor. When winter temperatures are here, you don't want to deal with issues heating your home. Waking up to a cold house or spending the day in a frigid office with a broken furnace can ruin your day. It can seem like your furnace goes out when you need it most.
What is the pilot light on a furnace?
Older furnaces used a pilot light to heat the air blowing into your home. Every year before the temperatures dropped, you probably noticed your parents bravely light the pilot light in the furnace. Today, the furnace igniter replaces the open flame of the pilot light in most furnaces.
Why does my furnace go out?
It can seem like your furnace goes out when you need it most. Even with preventive maintenance, your furnace can misbehave on the coldest days of the year. Sometimes it's a quick fix. In other cases, you could have a faulty furnace ignitor.
Why does my furnace stop blowing?
Check the air filter. If it's dirty, air can't flow properly through the furnace. This could cause your furnace to stop blowing.
How Does the Furnace Ignitor Work?
The furnace ignitor is the sole ignition mechanism on modern hot surface furnaces. A hot surface ignition furnace is different from the traditional standing pilot and intermittent spark ignition systems. A silicon-carbide or silicon nitride igniter piece replaces the standing pilot or spark plug.
What Happens When the Furnace Ignitor Goes Bad?
Several things can happen when you have a bad furnace ignitor. However, the standard outcome is usually cold air from your ducts. Why? Because heating cannot go on without furnace ignition. You need the ignitor to light the burners, which, in turn, produce the heat to warm your rooms.
How does a furnace igniter work?
This is where the hot surface igniter comes into play. The furnace’s control board allows electrical energy to flow to the igniter, which can soon be seen glowing red hot. To ensure that it has reached a sufficient temperature, a certain amount of time is allowed to pass before the gas valve opens up. Once the gas has begun flowing into the burners, it is quickly ignited by the hot surface. As soon as combustion has been initiated, electricity ceases to flow to the hot surface igniter.
What is a hot surface igniter?
This component utilizes electrical energy to start off the process of combustion. In this article you will learn more about how a hot surface igniter accomplishes this task.
What happens when a furnace is called for heat?
The first thing that happens when your furnace receives a call for heat is that the induced draft motor starts up. This ensure that, once combustion has started, the exhaust by-products will be safely vented out of your home.
What is a flame sensor?
For optimum safety, a hot surface ignition system utilizes what is known as a flame sensor. The flame sensor is able to detect the heat caused by combustion. When it does, it sends the signal to stop powering the hot surface igniter.
How does a flame sensor work in a furnace?
The flame sensor senses the fire and continues allowing the gas valve to feed gas to the burners. It stops feeding voltage to the hot surface igniter. When the thermostat satisfies, the gas valve closes. The blower runs for a time dissipating the heat in the furnace and then shuts down.
How does a pressure switch engage a hot surface igniter?
As soon as the control board verifies all safeties are good and the pressure switch is closed, it engages the hot surface igniter by energizing it with voltage
What is flame rectification?
For flame verification, we will use flame rectification. What is flame rectification? Flame rectification uses a flame sensor to detect a minimal amount of amperage generated by the flame. The microamps pass through the flame sensor and are detected in the ignition control board.
What temperature does a propane igniter need to be?
For natural gas or propane, that temperature is over 1200°F. When voltage is applied to a hot surface igniter, the temperature exceeds 2000° F. Therefore; hot surface ignition ensures we will light the gas.
What type of ignition is a pilot ignition?
Pilot Ignition. There are different types of hot surface ignition. First, most hot surface igniters operate off of 120-volts. There are some manufacturers the make 230-volt hot surface igniters. Additionally, Honeywell makes, what they call, a Smart Valve.
Can you touch the ignition portion of a hot surface ignition?
Never touch the ignition portion of the hot surface igniter. Finally, vibration and shock need to be taken into account for the hot surface ignition system. Too much shock or vibration can cause cracks in either type of system described above.
Can you touch a Honeywell hot surface igniter?
I was told by a Honeywell engineer that it is not true. Either way, whether true or not, it is still a good idea to handle it with care. Never touch the ignition portion of the hot surface igniter.
