Furnace Tries To Start Then Shuts Down

If the heat exchanger (highlighted above) gets too hot, the furnace shuts down. except the Flame turn on for 30 sec then the flame die. Normally there are two possible scenarios where the furnace would start clicking. Remember, if you give up now, you'll be like that old furnace that tries and then just shuts down. Simply unscrew, then unattach the electrical wires from the metal connectors. • Blower runs for 15-30 seconds then burner will fire up. It may need to be replaced. Also check batteries arenot corroding and have corroded the battery contacts so they arenot conducting electricity. As soon as the weather improves then furnace works great. 2) Furnace overheated Let's say your furnace blows hot air, then cold air, but then stops blowing any air at all after a while. Humming at Slow Speeds. Here is a test. Cold air blows out it will run for an hour or two and before it gets to temp the blower motor shuts off while the compressor continues to run. I had a very similar problem with my Suburban furnace. The dirty filter decreases airflow over your furnace’s heat exchanger (the part that actually heats the air). The only difference was after the burner shut down the fan would try to stop (hesitate) every 90 seconds. I had to manually restart from the thermostat to get it going again. Then the main blower starts working and the whole thing stays on for 2-3 minutes. But after that it did not shut down in what I thought a reasonable amount of time considering the temp was set about 20 degrees below the interior temp. I'm a new(ish) homeowner so I never noticed such things before, but I installed a thermostat, a Honeywell from HD that ran about $60, and the thing turns the furnace on about every 10 minutes and runs it for 7-8 minutes. The wiring in the inducer motor or in the thermostat may at the root of the problem. Then I turn on the heat using my thermostat and set the temp and then it works right. As you can see, if there’s a malfunction at step 4, your furnace won’t open the gas valve, and the burners won’t light. When you try to turn your furnace on, and nothing happens, you know something is wrong. I have a heat pump that pumps out 15BTUs of heat so have rarely used my furnace, but when it gets down into the 30s the heat pump automatically shuts off. noise on start up and shut down pan would lift up and bang down after it shuts off. We replaced the furnace,it's a heating oil furnace with boiler. York furnace. But then the flame will begin to die down, then spit and then go out. After a few seconds running. As soon as the weather improves then furnace works great. It can even be downright frustrating when you can hear the furnace actually clicking ‘on,’ and trying to blow warm air… but then it just shuts down. If your oil furnace runs then shuts off, you will first need to locate the reset button on your furnace to get it running again. On the battery side it would get "further" in the process (like the fan started to spin up) but then shut off and try again. Did get it to shut down by turning unit off. " It turns on for a few seconds to a minute, then turns itself off again. TO COMPLETELY SHUT DOWN. It worked fine for the few times we had to turn it on in the mornings. • Blower runs for 15-30 seconds then burner will fire up. One note of caution, since the thermocouple takes up to 20 seconds or so to cool down if you turned it off and on again very quickly gas would be f. I hear the blowers at least try to go. Later, the furnace will try to turn on again, overheat, then shut down again. When your home becomes cold a short time later, your furnace starts up again. On the surge only side it did the same thing it had been doing. It won't immediately turn back on, almost as if it has to cool back down first. Anyone help me out as far as what made it do that. Haier Furnace shuts off before reaching target temp [ 4 Answers ] Hi All, A few months ago my furnace was set to heat at 72 and before reaching the temperature, it cycled on/off three times and then shut off. Burners continue to work, temp continues to rise until it reaches "High-Limit" (around 180F), then the gas is cut off, fan continues to run until it cools down to minimum (around 120F) then furnace shuts off. Oil Furnace. If there is 220 volts going to the motor and the capacitor checks good then it is time to replace the motor and capacitor. getresponse. Goodman CKJ48-1AB Thought that AC wasnt cooling 100%, and low and behold went outside and condenser fan was not turning and fan was hot as well as entire unit. Atwood/Hydro Flame 8525-IV-DCLP Furnace: Bob: 1-12-06 : The furnace is in a 2005 Layton 3260. The flame lights on each attempt but after two seconds it goes out. The problem I was trying to fix was intermittent, where the furnace would fire up, then sometimes shut back down for no apparent reason. The Draft Motor Runs, Furnace Won't Start. turned out that the wires were ok but I was looking at the Saftey Shut Off Switch. When turned on, the fan comes on and the burner ignites normally, but the burner shuts off after a few seconds. Right before the heat kicks on each time, there is a loud bang that comes from the furnace. The draft motor is also called the inducer motor. Your furnace will go off on high limit continuously because it is not getting enough airflow through the heat exchanger. Your rv furnace may be the most tempermental appliance in your rv. The furnace begins to go through all of its "pre-cycle" steps it normally goes through: 1. if it isnt it could be either the motor or the little "MOTHER BOARD" that tells it when to kick on. Don't try and fix this problem yourself — instead, speak to an expert in oil furnace repair. The dirty filter decreases airflow over your furnace's heat exchanger (the part that actually heats the air). I have a heat pump that pumps out 15BTUs of heat so have rarely used my furnace, but when it gets down into the 30s the heat pump automatically shuts off. About a month ago I completely shut off the power to the furnace through the breaker box and shut the switch off on the furnace to reset it. The furnace works great for 15 minutes, then the fan quits and tries to restart a few times then totally shuts down. Ceiling fans can also help circulate warm air. After a few seconds or minutes, the furnace then clicks on again, and the cycle repeats itself. If it has a standing pilot you will need to relight the pilot before you can use the furnace again. Replace the limit switche(s). One note of caution, since the thermocouple takes up to 20 seconds or so to cool down if you turned it off and on again very quickly gas would be f. CAUTION Furnace is not to be installed, operated, and then turned off and left turned off in an unoccupied structure during winter. If the heat exchanger (highlighted above) gets too hot, the furnace shuts down. I have replaced the flame sensor and the automatic limit switch inside the box. At the time the furnace shuts off, the pipes coming out of the furnace are hot for about 4 feet (up until the first red "tap", then all the other pipes are cold). Regarding the burning smell from the return vents - what happened was the furnace would run for a while and then shut down - then the smell from the "burning" motor would waft up through the return shaft to the intake vent on the second floor of the house - it was a distinct warm burning smell emanating from the return vent. Once in about 3 times trying to start, the t-stat STILL shuts down during the ignition attempt, causing a failed ignition (because it opens the switch which closes the gas valve etc) and starting the whole startup cycle all over again 2 seconds later. It will then cycle off as normal. Short cycling is when the furnace will kick on for a few seconds, then shut off for a few seconds, then back on, then back off, repeat indefinitely. Most air-conditioning units last about 12 to 15 years, while a furnace usually goes for 15 to 20, so there’s a decent chance that one will need to be replaced before the other. A common cause of this is a problem with the motor bearings. Any help would be appreciated. Thermocouples detect pilot lights by sensing the heat they produce. With the clicking you can also hear it make the swoosh noise it makes when the burner initially ignites, only it comes in several intervals with the clicking. Furnace ignites and stays on for 5 sec then shuts off for about 30 sec. I again forced the fan to rotate and it started to loosen up. Oil-Furnace Repair and Troubleshooting When your oil furnaces quits, try some home diagnoses before calling in a professional, including these five tips and symptoms. However, by the time you've used our troubleshooting guide and watched our professional repair videos, you'll have more confidence. Read honest and unbiased product reviews from our users. If the filter is filthy, you've most likely discovered the cause of the shutdown. If the Fan-Limit switch FAN-ON setting is too high then the heat exchanger may be too hot by the time the blower fan turns on. Central heater furnace starts and blower starts for 30 minutes and then fan shuts off [ 1 Answers ] We start our central heater and the furnace kicks in and then the blower starts and the house warms up but when it reaches the desired temperature. Killing Galette Krone only shuts it down for a few seconds. Tried turning on the heat for the first time since it's getting colder now, I hear the click on the thermostat, but no air through the vents. if i were to have to take a guess i would look at the blower motot first make sure it is kicking on. Replaced that. [/list] I have tried reseting the circuit breaker on the interior control panel of the furnace. If your furnace clicks on or initiates the start cycle, but does not fire up, Step 3. Furnace Filter: Though less common it is possible for a badly clogged filter to cause your furnace to shut down. With little air to exchange heat to, the heat exchanger overheats, causing a limit switch to shut the gas valve. It starts and does heat but it is only staying on for a few minutes and then it shuts off. But if the filter remains clogged and the furnace overheats four or more times (the actual number varies by manufacturer), the computer will shut down the furnace until it's repaired. That thermo switch opens if the furnace gets too hot and shuts down the gas. This guide discusses the common problems related to a motor that won't start or once it does start shuts off after 5 minutes. Your furnace tries this ignition sequence again, and the same thing happens. Its circuit board failed just barely out of warranty. Try putting the blower to ON at stat, this might give you A/C speed which generally is higher than heat. If the Fan-Limit switch FAN-ON setting is too high then the heat exchanger may be too hot by the time the blower fan turns on. So I then go to the furnace room and I hear motors running but not the fan nor do I hear any gas either. I went down to check the furnace and I see that it's trying to start, but after a few minutes or so, it just shuts down. We've had HVAC people come to look at it but the problem never goes away when they are done with it. Why Is My System Making a Clicking Sound Like It’s Trying To Start But Doesn’t? The noises are related to the furnace going through its startup sequence. If you own a gas furnace, keeping the unit in top running condition is important for the safety of the home’s occupants. It's been working perfectly since. After 3 times the furnace goes into lockout, and the only way to get it out of lockout is to turn the power switch off and on. I shut off the blower/motor and the furnace stopped then replaced the two wires and tightened them down properly. I have an 8500-IV series Atwood furnace. (I turn my thermostat all the way down, turn the gas valve on, turn the breaker switch back to "ON", then turn my thermostat to the temp I want and voila' - it works Am I Mismatching T he Furnace A nd Thermostat:. If your furnace […]. model - gy8s080a12uh11c. What do I do now? If it has turned on and off a couple times and goes into a lockout mode, you have to turn the furnace off and back on to be able to. If the flame sensor does not detect a flame, the co ntrol board will shut off voltage to the gas valve to prevent the furnace from heating. If the air coming out is cold when it should be warm, you should call an HVAC contractor. Apply duct tape to any loose ducts or other pieces of the equipment. I went down to check the furnace and I see that it's trying to start, but after a few minutes or so, it just shuts down. If the sensor does not detect a satisfactory flame within about 10 seconds, the board then shuts off the gas valves and discontinues the ignition spark. A furnace by definition provides heat. Not only does this decrease your comfort, it can damage your furnace. So why is my furnace not staying on? Maybe or maybe not your flame sensor may perhaps be the problem. If it starts and then the furnace shuts down, the cause might be: The motor or the board that controls it has failed and must be replaced. Heat pump works fine, but the when I switch the thermostat over to gas heat the fan runs for 20-30 seconds and then the furnace turns off. com Search. Then the fan seems to freeze and I have to start all over again. Oil-Furnace Repair and Troubleshooting When your oil furnaces quits, try some home diagnoses before calling in a professional, including these five tips and symptoms. I had to manually restart from the thermostat to get it going again. Other troubleshooting and maintenance steps may solve your problems before you must resort to the expensive solution of calling in the pros. Otherwise, your furnace won't start. If your furnace making a clicking noise when it is ready to shut down after running a full cycle, the blower shuts off then the clicking starts. I swap out the controller with a spare I bought, no go. If your furnace lights and the gas stays on for 8 to 10 seconds, then shuts right back off, then you can try to clean your flame sensor with light sand paper (emery cloth) or steel wool. It worked fine for the few times we had to turn it on in the mornings. Keep pressing down on the bypass button for 30 seconds after the pilot flame is ignited and then release. Following the instructions on your furnace, proceed to start it up again. Furnace Filter: Though less common it is possible for a badly clogged filter to cause your furnace to shut down. It also will shut the furnace down for a about five minutes after an hours running time, I'm not really sure why as this doesn't get mentioned in anything I've read on these. Rheem Criterion II Gas Furnace that shuts down when temp is reached? We have a Criterion II Gas Furnace. This article series discusses how to inspect and test a heating or air conditioning indoor air handler blower fan that is not working. Heater comes on then shuts off. You have to wait a few minutes again before the furnace will restart. Try to pinpoint where the rattling noise is coming from inside the air duct system then shut down the heat pump and try to remove the debris. Furnace apparently came on and didn't ever shut off. Sometimes it comes on by itself, other times I have to go downstairs and bang the top of the furnace to get it to kick on. At the end of the heating process, it waits until the internal air temperature drops below its predetermined level, then shuts down the fan until the next heating cycle begins. So if the blower fan does start, but the unit does not light, then you either have low voltage to. A/C and heat unit makes "slamming" noise when stops. One note of caution, since the thermocouple takes up to 20 seconds or so to cool down if you turned it off and on again very quickly gas would be f. the Fan and everything is still run. FIXED: Furnace shuts off after 30 seconds Have had this conversation going in another topic, but thought I'd start this in it's own thread. The furnace starts to heat the home, but turns off again quickly after only a short amount of time has passed. If the Fan-Limit switch FAN-ON setting is too high then the heat exchanger may be too hot by the time the blower fan turns on. If you are not successfully locating the noise causing debris, then call an HVAC professional to come to get it out for you. Why Is My System Making a Clicking Sound Like It’s Trying To Start But Doesn’t? The noises are related to the furnace going through its startup sequence. There is very little that an untrained person can do, without risking engulfing his home in an enormous ball of flame. Tried fuse, waiting and turning back on. If your fan limit switch was already set to AUTO (not pressed in), then you most likely either have a problem with your thermostat wiring or the fan limit switch is bad. From time to time it decides to stop running and won't start up again. You can clean the flame sensor yourself if you feel alright opening up your furnace. You may have to remove a register cover or vent cover to get to the debris. Then the sequence starts all over again with no ignition of the gas: My furnace's ignitor does not glow? This could be a pressure switch, limit, roll out switch, or furnace control board problem. The furnace repair guy came and he says it is the fault of the radiator installer, that there is air in the system so the water won't circulate so it gets too hot and shuts down. Thought it was the control box, replaced that. In case of furnace malfunction, you may need to shut it down. Anyone familiar with floor furnace dating back around the '40's ? It is working,, but I need to shut off the gas to entire house to replace a leaking shutoff valve elsewhere, (behind stove) But I want to be able to re-light the pilot on this furnace after I do that. It also will shut the furnace down for a about five minutes after an hours running time, I'm not really sure why as this doesn't get mentioned in anything I've read on these. When the fan tries to restart it spins really slowly, also the interior trailer lights flash (dims) when the fan is trying to restart. Then try to cycle it several times and see if it starts. It still has a gradual heat and cool down cycle lasting about 45 minutes, and the hot air movement from the grills is still mild and gradual perhaps double what it originally was. Then, as before, a lot of time goes by and the furnace won't come back on by itself. 15) Open the furnace (wearing the proper safety equipment) and proceed with your pour. turned out that the wires were ok but I was looking at the Saftey Shut Off Switch. Most likely, your furnace is making a clicking noise and not providing heat because your furnace's spark igniter is trying to ignite your pilot light or burners but is failing to do so. Turn OFF the main gas supply to the appliance at the manual valve, outside of the appliance cabinet. The thermostat is set for 75 and the room temp is 70. Then I turn on the heat using my thermostat and set the temp and then it works right. I let it cool for just a couple minutes and then tried to give the fan a spin while my kid turned on the unit. The furnace sounds like it is trying a couple of times to light but then times out and shuts down which is good. Possible problems are insufficient air flow through the furnace a bad propane valve at the furnace or a bad regulator at the propane tank. If you suspect a hole shut down your furnace immediately until you can test it. Call your nearest U-FIX-IT Appliance Parts store if you have any more questions. Anyone help me out as far as what made it do that. If the filter is filthy, you've most likely discovered the cause of the shutdown. When the furnace lights, the glow ignitor starts first and the pilot light automatically ignites. I am hoping someone may have an idea about why this is happening and how to stop it. Pilot stays on but the furnace doesn’t come on, step 2. About a month ago I completely shut off the power to the furnace through the breaker box and shut the switch off on the furnace to reset it. If the flame sensor does not detect a flame, the co ntrol board will shut off voltage to the gas valve to prevent the furnace from heating. 4 the fans continue to run until the furnace cools down, then the furnace heat sensor shuts the fans off. model - gy8s080a12uh11c. Eventually the hi temp sensor will kick in and turn the gas off. The only difference was after the burner shut down the fan would try to stop (hesitate) every 90 seconds. I have an intermitent problem with a 2-year old Carrier natural gaz furnace. com My furnace turns on then shuts off. Furnace shuts down– Because your furnace has to run longer to heat your home, the heat exchanger overheats, causing the furnace to automatically shut down. coach warms to set temp and flame shuts off, furnace goes into cool down cycle. Your furnace has what is called "soft lockout" it usually on most models is one hour. Short cycling is when the furnace will kick on for a few seconds, then shut off for a few seconds, then back on, then back off, repeat indefinitely. Your utility company may have raised their rates. Ok, that's 2 questions. Exhaust fan kicks on and runs for 10-15 secs 2. The draft motor is also called the inducer motor. A furnace by definition provides heat. If the propane is shut off or runs out depending on the setup of the propane heater. Short cycling is when the furnace will kick on for a few seconds, then shut off for a few seconds, then back on, then back off, repeat indefinitely. Problem: Furnace main burner ignites, the main burner stays on for 8 to 10 seconds, then shuts right back off. I have an Atwood 8531 Hydroflame furnace, orginal to a 2005 Tioga 22B class "c" RV. If it has a standing pilot you will need to relight the pilot before you can use the furnace again. A lockout code will be displayed on the IFC. The furnace starts to heat the home, but turns off again quickly after only a short amount of time has passed. The other item to check which is normally beyond what a normal person can do is to verify that you have gas going to the burner. After a few seconds or minutes, the furnace then clicks on again, and the cycle repeats itself. Then, the blower motor seems to try to run every 10 minutes or so. A furnace can also make intermittent sounds like it's turning itself on and off. my furnace runs for about 1 minute and then shuts off before it reaches set temperature. if it isnt it could be either the motor or the little "MOTHER BOARD" that tells it when to kick on. Electronic Ignition Furnace. When you try to turn your furnace on, and nothing happens, you know something is wrong. Then I turn on the heat using my thermostat and set the temp and then it works right. (Should be small 18 gauge wires white and red). This particular unit, should there be a shut down due to no flame, will attempt a restart after 2 minutes. Try cleaning the flame sensor with a fine abrasive pad. Burners continue to work, temp continues to rise until it reaches "High-Limit" (around 180F), then the gas is cut off, fan continues to run until it cools down to minimum (around 120F) then furnace shuts off. A lockout code will be displayed on the IFC. With the front panel off the furnace will run thru full cycle but only runs about 5 min since it is under the thermostat. My furnace blower doesn't always start. If you suspect a hole shut down your furnace immediately until you can test it. After sitting in the storage yard for weeks on end, it always fails initial start up. the furnace turn on for a few minutes. Then the sequence starts all over again with no ignition of the gas: My furnace's ignitor does not glow? This could be a pressure switch, limit, roll out switch, or furnace control board problem. never had a problem until today. i set the thermostat i hear it click, the blower starts. Once the heat exchanger overheats, it trips the high limit switch, which shuts the furnace down to protect it. I replaced new pressure switch, igniter, and I also cleaned the flame sensor but that didn't resolve the issue. By continuing to use this site you consent to the use of cookies on your device as described in our cookie policy unless you have disabled them. I have to wait quite a while with the thermostat Off and then try again. The heater will burn for awhile heating up the water to 170 degrees, and seems fine. The furnace tries a total of 3 times, then if flame is not established goes into hard lockout. This will cause the fan to automatically turn on when the furnace is heating and shut off once the call for heat stops. Also LED on furnace blinks {short, long, long and then repeats. The blower kicks on for about five seconds then shuts down right away. For most furnaces, the inducer motor starts up before it ignites and the blower motor engages once the air is hot enough to distribute. The fan may not turn on because of a bad relay switch on the control board or damage to the transformer. My furnace blower doesn't always start. Then the van warms up, and the thermostat shuts the furnace off. Expecially in the morning, when the house temperature is at 65 degrees, the furnace fails to turn on despite the fact that the thermostat is sending the proper signal. Tried turning on the heat for the first time since it's getting colder now, I hear the click on the thermostat, but no air through the vents. SOURCE: furnace starts properly, then shuts down, led flashes 8 times. I then have to turn the power off to the furnace and turn it back on. So, I read on Google what I highlighted for you, and ordered a 30+ UF cap. How to Tell if an Ignitor on a Gas Furnace Is Working. If your furnace shuts off when you turn the thermostat to off, a possible cause is a malfunctioning thermostat and replacing it should fix your problem. No gas = no flames. Lighting the Furnace, and start at #2. If the furnace fires but the blower doesn't start, its motor may be bad. I had a very similar problem with my Suburban furnace. All furnaces built in the last decade have ignition control boards or circuit boards that control the safety and operation of the furnace. if it isnt it could be either the motor or the little "MOTHER BOARD" that tells it when to kick on. Goodman high efficiency furnace. You absolutely cannot live without a furnace in cold weather. I have a peerless cast iron boiler with a becket burner. It would try to ignite 3 times before locking out and requiring a thermostat reset. My furnace in not working right. If the furnace isn't getting enough air, it will shut down. It sounds as though it wants to start then shuts down only to try again in a short while. It's normal for burner to cycle on and off. How to Restart a Furnace After Running out of Oil. The furnace tries a total of 3 times, then if flame is not established goes into hard lockout. The fire took the shape of a vault, like a ship’s sail bellying in the wind, and it made a wall round the martyr’s body; and there was the a body in the midst, like a loaf being baked or like gold and silver being tried in the furnace. If dirt or dust covers the sensor, the flame isn’t detected, and the furnace shuts down. After trying a few thing, even exchanging the CAD light, it will not stay running. That thermo switch opens if the furnace gets too hot and shuts down the gas. " It turns on for a few seconds to a minute, then turns itself off again. Unscrew the rod and use your sandpaper, steel wool or emery cloth to gently clean the metal rod. Regarding the burning smell from the return vents - what happened was the furnace would run for a while and then shut down - then the smell from the "burning" motor would waft up through the return shaft to the intake vent on the second floor of the house - it was a distinct warm burning smell emanating from the return vent. If this is your first visit, be sure to check out the FAQ by clicking the link above. When it is cold outside, and the furnace won’t fire up, it can be concerning. I wish I had read the other reviews before making my purchase. Electronic Ignition Gas Furnace Problems & Troubleshooting In any case, many things can happen in that furnace sequence of operation that can prevent the gas furnace from providing heat. Sometimes it works till the desired heat is achieved, other times it just cuts out randomly as if it were bored or tired of doing its job. Furnace shuts off - won't restart without reset house will cool off until we "kick-start" it by turning the thermostat off then on. For other units, the furnace will continue to run but with less heat. The furnace starts to heat the home, but turns off again quickly after only a short amount of time has passed. it shuts off. If the furnace starts up, then the microtemp needs to be repalced. I have replaced the flame sensor and the automatic limit switch inside the box. Most air-conditioning units last about 12 to 15 years, while a furnace usually goes for 15 to 20, so there’s a decent chance that one will need to be replaced before the other. if i were to have to take a guess i would look at the blower motot first make sure it is kicking on. Replace it with a new one. The furnace goes off on high limit to keep from overheating the furnace and possibly causing a fire. As a test I brought down my battery backup/UPS and tried to connect that to the extension cord and the furnace to the UPS. Then the boiler shuts down. Call your nearest U-FIX-IT Appliance Parts store if you have any more questions. Open your furnace’s front panel and trace the wire to the flame sensor, which looks like a thin, bent rod. The high-limit switch reaches its low-temperature setting. coach warms to set temp and flame shuts off, furnace goes into cool down cycle. If the flame sensor does not detect a flame, the control board will shut off voltage to the gas valve to prevent the furnace from heating. Fortunately, you're usually able to make it function normally again by simply resetting it once. Before you attempt to fix a furnace that won't start, make sure you know what kind Step 2. the furnace turn on for a few minutes. LED is flashing on-off continuously at about the rate your cursor flashes on your computer, the manual says this is normal "cal for heat". will go thru this for a 1/2 hr to an hourthen it will go on without a problemsounds like an igniter. About a month ago I completely shut off the power to the furnace through the breaker box and shut the switch off on the furnace to reset it. How To Determine Why a Motor Won't Start or Shuts Off - INYOPools. My furnace does not have an automatic pilot, I have to manually light the furnace. This can make the first start up difficult, since it will take several cycles to bleed the air out of the line. The circuit board monitors the burn cycle through a sensor that detects the presence of the flame. 20 Seconds is the give away here, telling me you have a single phase motor. I replaced new pressure switch, igniter, and I also cleaned the flame sensor but that didn't resolve the issue. Goodman high efficiency furnace. I didn't think a simple timer would do it because I just don't think that would allow enough "working time" to get the house actually heated. Flame sensor rod was not dirty or discolored hardly at all, but cleaned it up with a dry Brillo Pad - no help - still shuts down soon after flame lights up. On the battery side it would get "further" in the process (like the fan started to spin up) but then shut off and try again. It occurs because after several attempts to light the furnace shuts down and then one hour later will try again. It sounds as though it wants to start then shuts down only to try again in a short while. (Should be small 18 gauge wires white and red). Shutdown definition is - the cessation or suspension of an operation or activity. To bypass, unplug the leads to the microtemp and use a jumper to connect the 2 leads. I have replaced the flame sensor and the automatic limit switch inside the box. With the front panel off the furnace will run thru full cycle but only runs about 5 min since it is under the thermostat. —your thermostat could be to blame. The pilot light switch may be mounted by a couple of screws. Oil-Furnace Repair and Troubleshooting When your oil furnaces quits, try some home diagnoses before calling in a professional, including these five tips and symptoms. The symptom was similar. Problem: Your furnace main burner ignites, the main burner stays on for 8 to 10 seconds, then shuts right back off. This will cause the pressure switch to shut the furnace down. Pretty sure the valve shut-off switch they are talking about is the on and off switch on the thermostat. That thermo switch opens if the furnace gets too hot and shuts down the gas. It starts and does heat but it is only staying on for a few minutes and then it shuts off. It's loud and it doesn't heat anything. Furnace tries to start but then shuts down. This guide discusses the common problems related to a motor that won't start or once it does start shuts off after 5 minutes. Pilot stays on but the furnace doesn’t come on, step 2. Sometimes the main blower shuts off and the combustion blower continues to cycle on and off several times. The only difference was after the burner shut down the fan would try to stop (hesitate) every 90 seconds. When turned on, the fan comes on and the burner ignites normally, but the burner shuts off after a few seconds. Beyond that point, it goes into lockout mode, will not retry for ignition until reset and the blower will continue to run. I installed that cap and the motor shut down in five minutes. If I close the panel too far the furnace will burn longer but flame out and go into lockout. You can clean the flame sensor yourself if you feel alright opening up your furnace. You trust your furnace to keep your home at the perfect temperature without having to think about it.