How does a hot surface igniter work?
Hot surface ignitor are the most commonly used electronic ignition system. It works like a light bulb filament, heating up when electricity is passed through it. Most are made from silicon nitride or silicon carbide ceramic. When the gas valve opens, the gas is ignited by the igniter. How work a hot surface igniter?
What is a surface ignitor on a gas fireplace?
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.
What is a hot surface ignitor (Hsi)?
Hot Surface Igniters are Resistance Heaters As mentioned earlier, hot surface ignitors, or HSI’s, are resistance heaters. The element itself glows orange when the voltage is applied. How hot that element gets depends on the voltage being applied to it.
What are the different types of hot surface igniters?
There are two specific types of hot surface igniters. The silicon nitride is considered the better of the two because it is less fragile. Hot surface igniters, being ceramic, are prone to breaking or cracking. Any hot surface igniter should be handled with care The largest problem with a hot surface ignition system is cracking.
How does a hot surface ignition work?
0:572:14Hot Surface Igniter - YouTubeYouTubeStart of suggested clipEnd of suggested clipBut this igniter is in the flame as in the airstream of the gas. Coming out of our gas furnace gasMoreBut this igniter is in the flame as in the airstream of the gas. Coming out of our gas furnace gas will blow across. This igniter this igniter will glow orange. It would get very very hot. Very very
What causes a hot surface ignitor to burn out?
One of the causes could be high supply voltage. A hot surface igniter can burn out at approximately 132 V. Even voltages in excess of 125 V may reduce igniter life. If high voltage is present, the power company should be requested to lower the power.
Is hot surface ignitor same as flame sensor?
As soon as combustion has been initiated, electricity ceases to flow to the hot surface igniter. For optimum safety, a hot surface ignition system utilizes what is known as a flame sensor.
How do I know if my hot surface ignitor is bad?
0:173:26How to test a Hot Surface Ignitor - YouTubeYouTubeStart of suggested clipEnd of suggested clipIf when tested you see no reading on your tester or your dial doesn't move if you have an analogMoreIf when tested you see no reading on your tester or your dial doesn't move if you have an analog gauge. This will indicate the igniter is bad it must be replaced.
How much does a hot surface igniter cost?
Igniter Cost: The igniter costs no more than $30 to $50. Check with your furnace manufacture for the model number of your furnace so you can find the right igniter for your unit.
How much does it cost to install a hot surface ignitor?
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 often do furnace ignitors fail?
On average, furnace ignitors will last about four to seven years. This depends upon how well maintained the system is. After the seven-year mark, you should replace it.
Can a hot surface ignitor be cleaned?
2:485:01Furnace Not Igniting - How To Clean your Hot Surface Ignitor - YouTubeYouTubeStart of suggested clipEnd of suggested clipNow you want to clean your hot surface igniter really good on the end. And you want to get rid ofMoreNow you want to clean your hot surface igniter really good on the end. And you want to get rid of this carbon buildup i like to use like 120 grit sandpaper. And you just take it all off with the
How long do hot surface igniters last?
Under normal operating conditions, a hot surface igniter will last 3-5 years. During the heating season, the hot surface igniter can go through a tremendous amount of use.
How do you reset a furnace ignitor?
Resetting The Ignitor Once the power is off you can remove the burner door to reveal the ignitor. Turn this to “off” and leave it off for at least 5 minutes. After this time, turn the ignitor back to the “on” position and replace the burner door. You can then turn the power source back on and restart the furnace.
Can you clean an ignitor?
Compressed Air To Clean The Igniter If your heating system has a spark ignitor and isn't working accurately, it may get coated in soot, and a blast of pressurized air may be all that's needed to clean it.
How do you replace a hot surface gas igniter?
0:402:14How to Replace a Furnace Ignitor - Hot Surface Ignitor - YouTubeYouTubeStart of suggested clipEnd of suggested clipOnce the screws are removed you can pull out the igniter. This style has two tabs that you need toMoreOnce the screws are removed you can pull out the igniter. This style has two tabs that you need to squeeze. So that you can pull apart the plug. And this disconnects the old igniter.
How long do hot surface igniters last?
Under normal operating conditions, a hot surface igniter will last 3-5 years. During the heating season, the hot surface igniter can go through a tremendous amount of use.
Why do igniters fail?
A power surge may negatively impact the ignitor and cause it to short-circuit. Most heaters may handle a range between 110 and 125 volts of electricity supply. Anything above that may cause the ignitor to fail.
How often do furnace ignitors fail?
On average, furnace ignitors will last about four to seven years. This depends upon how well maintained the system is. After the seven-year mark, you should replace it.
Can a hot surface ignitor be cleaned?
2:485:01Furnace Not Igniting - How To Clean your Hot Surface Ignitor - YouTubeYouTubeStart of suggested clipEnd of suggested clipNow you want to clean your hot surface igniter really good on the end. And you want to get rid ofMoreNow you want to clean your hot surface igniter really good on the end. And you want to get rid of this carbon buildup i like to use like 120 grit sandpaper. And you just take it all off with the
How does a hot surface igniter work?
Hot Surface Ignition systems use an 'M' or fork-shaped silicon carbide or silicon nitride igniter piece instead of a traditional spark igniter to light your gas flames. Low-voltage, but high-current electricity is sent through the hot surface igniter piece, heating it up to a glowing 2500 degrees Fahrenheit. After an approximate five second delay to allow the igniter to heat up, the gas valve opens to allow the gas to flow through. Since natural gas lights without a spark at around 1163 degrees and propane between 920 and 1020 degrees Fahrenheit, the heat from the electrical current will cause combustion in either gases and ignite the pilot system. Another five second delay allows the application to run a system check to ensure the pilot was safely lit and the gas is circulating appropriately. Once the flame sensing technology confirms the pilot is lit, it will allow gas to flow to the burner and ignite flames to the entire system. If the pilot does not light, the application will automatically shut-off the gas valve to avoid risk of explosion. These flame sensors use a thermocouple to detect the burner flame. An extremely small, alternating electrical current is sent to the sensor from the control module and in turn, the sensor converts it to a direct current. This signals to the control module that a flame is present. If a flame is not present, the system will attempt to relight the fire three times before shutting down the gas source.
How to operate a hot surface igniter?
Hot surface igniter operation is as simple as a flip of a switch! Simply turn on your electronic ignition system with the wall switch, remote, or timer installed with your burner application. This sends an electronic signal to the hot surface igniter to begin its safety checks and start the flow of the pilot gas. Once the thermocouple confirms that the pilot flame is safely lit, gas will flow to the main burner and light your fire!
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 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.
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.
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 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.
Which is better, silicon carbide or silicon nitride?
Silicon Carbide Igniters. Silicon Nitride Igniters. The silicon nitride is considered the better of the two because it is less fragile. Hot surface igniters, being ceramic, are prone to breaking or cracking. Any hot surface igniter should be handled with care.
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.
What is a hot surface igniter?
A silicon nitride hot surface igniter is a device to light gas in gas burner, gas furnace or gas boiler appliances.
How do I know if my hot surface ignitor is bad? How do you test a hot surface ignitor?
As a hot surface igniter is a resistance (thermal resistance producing heat), the only way to check if an ignitor is bad or broken is to check the resistance value.
How do you replace a hot surface ignitor?
Every appliances, furnace and burner are different. Please consult the appliance manual or call a professional to do the replacement.
How do I clean the igniter on my furnace?
Insert the straw taped to the side of the can of compressed air into the nozzle of the can. Hold the can upright 12 inches from the ceramic ignitor. Tap the release button on the can to send a few short bursts of air onto the ignitor to clean away any dust.
What does a furnace ignitor look like?
Common silicon nitride hot surface ignitor looks like the picture below.
How long does a silicon nitride igniter last?
It depend on the appliances, number of ignition and temperature, but silicon nitride igniter have an average lifespan of 7 to 15 years.
What is a PTC ignitor?
Silicon nitride ceramic hot surface ignitor are PTC ceramic elements: PTC ceramic materials are named for their positive thermal coefficient of resistance (i.e., resistance increases upon heating). That mean that they have a highly nonlinear thermal response, so that above a composition-dependent threshold temperature their resistance increases rapidly. This behavior causes the material to act as its own thermostat, since current passes when it is cool, and does not when it is too hot, so the temperature stabilize at a certain tempereture (1100~1400°C).
What is the difference between a hot surface igniter and a direct main igniter?
On the other hand, a hot surface igniter system that lights a pilot light first and allows the pilot to light the main burner will allow less gas into the atmosphere when the pilot valve inside the gas valve opens. In contrast, a direct main burner ignition system is going to open the valve and allow more gas into the atmosphere. That would create a hazard if something were to go wrong with the hot surface igniter by allowing more gas into the atmosphere.
How to test a hot surface ignitor?
Hot Surface Igniter Voltage Test: You disconnect the old hot surface ignitor and place your meter leads on the wires coming from the board. You energize the furnace on a call for heat and make sure you get the proper amount of voltage from the board. To be safe, I would turn the gas supply off to ensure no gas is released during the test. Additionally, make sure you take care not to get shocked during this process. After all, this is a live voltage test.
Why is my surface igniter not working?
The ignition problem could be one of many problems that are caused by either a malfunctioning part in the gas furnace or a problem with the fuel supply for the gas furnace.
What are the safety factors of electronic ignition?
Safety Factors of Electronic Ignition: Hot Surface Ignitor - Ignition. A vast majority of hot surface ignition systems light the main burners directly without using a pilot light. That is a simpler form of using a hot surface ignitor to light a pilot light. Then the pilot light lights the main burner.
How many volts does a hot surface igniter need?
When replacing a hot surface igniter, it is important to know the supply volts needed for the new igniter. Most hot surface ignitors work off of 120 volts. However, there are a few out there that work off of 240 volts. The Honeywell SmartValve Hot Surface Pilot Ignition uses 24 volts.
How to see if gas igniter is red hot?
One can view this operation by observing the hot surface igniter glowing red hot. After a specific amount of time, the gas burner control board opens the gas valve allowing for gas to flow to the main burners. When the gas reaches the main burners and hot surface igniter, the gas begins to burn.
What does the gas burner control board do?
After a specific amount of time, the gas burner control board opens the gas valve allowing for gas to flow to the main burners.
Why does my igniter burn out?
There are several possible causes for repeated igniter failures. One of the causes could be high supply voltage. A hot surface igniter can burn out at approximately 132 V. Even voltages in excess of 125 V may reduce igniter life. If high voltage is present, the power company should be requested to lower the power. 3.
How to check if an igniter is bad?
1. Do a visual check of the igniter for signs of damage or cracks. The sleeving over the wire should be examined for chafing, burned portions, or cuts in the wire. The connectors should be properly seated and free from oxidation and/or corrosion. Look for hot spots on the igniter. Observe the igniter during heat up. If a bright, white line across one of the igniter legs is detected, a crack may exist that could cause premature failure.
How long does the igniter stay on?
The igniter will remain on for a specific amount of time (seconds) depending on the specific ignition module being used. This “on” time or trial for ignition time can vary, depending on the specific ignition module being used.
How to tell if a spark plug igniter is cracked?
Allow the igniter to cool and perform a resistance test. Addi-tional signs of a crack are an “open” igniter (show s no continuity when tested), or a buildup of white silica dust around the bright spot. Replace the igniter if you see these cracks.
What causes a drywall igniter to fail?
In some cases, condensate dripping on the igniter causes it to fail .
How long does it take for a silicon carbide igniter to heat up?
Once the prepurge timing is up (if so equipped), the silicon carbide igniter heats up to a proper ignition temperature (above 1,800°F) in either 17 or 34 sec, 20 or 40 sec for some models (depending on the manufacturer of the module).
What causes a boiler igniter to be shortened?
4. Furnace or boiler short cycling, delayed ignition, or an overgassed condition also contribute to shortened igniter life.
How Long Do Hot Surface Igniters Last?
Different hot surface igniters last longer than others. The trend over the last five to ten years has been to use the more durable silicon nitride igniters. They seem to be less brittle, making them better able to stand the test of time.
How do nitride igniters work?
Most nitride igniters are formed in the shape of a 1.5-inch flat stick or a 2-inch long cylinder. When the voltage is applied to the wires, the element starts to glow because of the resistance the carbide creates from one wire to the next. When it glows long enough, gas is poured over it, and the flame ignites.
Why do silicon carbide igniters break?
So why do these silicon carbide igniters break so often? The fact is, a gas flame pours over these ignitors which applies a lot of damaging heat to them. The same thing that makes them work also destroys them!
How many volts should an Hsi have?
An 80-volt HSI should have about 80 volts applied to it. Applying 120 volts to that HSI will cause it break, and sometimes almost immediately. Having too low of voltage may not let the igniter burn hot enough. Once, in my early service years, I replaced a 240 ignitor for a package unit with a 120 ignitor.
What is the sequence of events that takes place for a gas furnace to start a flame that jets into the?
To technicians and furnace manufacturers everywhere, the sequence of events that takes place for a gas furnace to start a flame that jets into the tubes of the heat exchanger is like a well-choreographed dance. Stick around while we talk about an integral part of the sequence to bring heat into a home: the hot surface igniter.
What temperature does a 120 volt HSI ignite?
A 120-volt HSI will glow at around 2500 degrees Fahrenheit. Most gas fuels will ignite around 1100 degrees, so 2500 degrees is a little excessive. A 240-volt igniter burns even hotter. Several control boards these days are made to support an 80-volt igniter.
Why does a carbide element glow?
When the voltage is applied to the wires, the element starts to glow because of the resistance the carbide creates from one wire to the next. When it glows long enough, gas is poured over it, and the flame ignites.
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.
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.
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 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.
Where is the ignitor located on a gas line?
Locate the ignitor, which is usually positioned near the gas port on a V-shaped bracket. If the ignitor has visible damage, there’s no need to test the part. Just replace it.
Can a dirty furnace ignitor prevent furnace from working?
A dirty ignitor can also prevent the furnace from operating well. Have regular inspections done to ensure it is in peak condition. It is possible for you to clean the ignitor yourself before calling in an expert.
