I swap out igniter, flame sensor, pressure switch and check high limit switch still good (normally closed) . If your furnace has a leak in the heat exchanger combustion gas is allowed to mix with air in your home or in with the blower motor air. I was going to order an inducer motor. I ordered a control board from your website already. I would like to suggest that the next time the draft inducer shuts off during the middle of a cycle to make sure you are getting low voltage (24 to 28 volts AC) from the thermostat between the W and C (com) wires. The vent pipe is a PVC (plastic) pipe typically extending out the side wall or through the roof of the house. Steve. Furnace pressure switch troubleshooting. Possible causes include blocked vent pipes, blocked air intake pipes, faulty pressure switch or pressure switch hose or a faulty combustion air blower. Hi Dan! Hello, love the website and help that it offers. So go ahead and put the hose back on, put the access panel back on the furnace, turn up the thermostat to its highest setting. Please make sure the fuse is not blown on the control board. Do not blow into a hose that is connected, as this can damage the pressure switch. Hi Barney! If you find that you have a hole in the heat exchanger then you need to replace the heat exchanger or get a new furnace because this creates a dangerous condition that can allow carbon monoxide into your home. The suction your furnace's pressure switch needs to … Our email address is. I would recommend that you check and test all safety controls like the limit and rollout switches to make sure they are all closed. Clean the pressure switch if it is stuck closed and check the vents for possible obstructions. (7) A leaking heat exchanger. Furnace Vent Air Pressure Switch - Replacement for Rheem ClimaTek Gas Part # 42-24335-02. I hope you can easily find and fix the problem. If the inducer is getting 120 volts and not running then you have a draft inducer problem. A furnace pressure switch is a safety device located near the draft inducer motor of a gas forced-air furnace. Pressure switch fails closed Normally this would indicate a failed pressure switch, The furnace will test to make sure the switch is open before starting the ventor motor. I ended up having to tear the 2″ pipe out and install 3″ PVC vent. I am shipping your control board out today. The pressure switch on a Lennox G16 gas furnace monitors whether the air blower is in operation. We sell this inducer on the following page: https://arnoldservice.com/product/0171m00001s-goodman-furnace-draft-inducer/ I hope you can easily find and fix the problem. The pressure switch must be replaced. This might free the switch from sticking. Took me 5 minutes and the switch was 60$. We have UPS Ground, Next Day Air Saver, 2nd Day Air, 3 Day Select and UPS Sure Post shipping options in our shopping cart. Touch each tester probe to one of the switch terminals. Thank you so very much for your business! I don’t believe that is the problem. Steve. When there is a vacuum, the pressure switch diaphragm pulls out and closes the switch. The sensor closes when the furnace kicks in and allows heat to enter into the home. Steve. Without testing with a meter it is a guess. Replace it. Thanks so much for your business!!! GMS90453BXA MODEL NUMBER. No residue on it. We have one of the Best in Website Security with a Norton Symantec Secured Website and Shopping Cart! We Have Promptly Shipped Over 350,000 Orders Since 2002! The rollout switch will not reset if it opens. The exhaust is not blocked leading outside. (5) a slow draft inducer that might need a new capacitor or has slowed down. If the allowed vent feet are exceeded then you will have trouble with the pressure switch not staying closed. Other times it works just fine…? Replaced pressure switch. Yes, It sounds like you either have a draft inducer problem or a control board problem. This may break loose the contacts inside. Reinstall the furnace access panel, and restore power to the furnace. How Does a Gas Furnace Pressure Switch work? I have a Carrier HE furnace that is not even 3 years old yet. And I have also cleaned the flame sensor with a newspaper (no steel wool). I would start by making sure the thermostat is providing 24 volts between W and C terminals on the control board when the furnace cuts off. The low-pressure switch should close and provide 24 volts AC between each of the two terminals on the pressure switch to a good ground. Place your order today! And again the pressure switch is brand new (supposedly). Use a flashlight to inspect inside the hose port on the pressure switch and make sure there are no obstructions. If you are getting a constant 24 to 28 volts AC to the furnace all the time between W and C when the furnace cuts off then this would eliminate the thermostat from being the problem. Thermostat calls for heat, inducer motor starts but not ignite and after 30 seconds I can smell gas. and after few minutes the inducer motor shut down and led light flashing 7 times. pressure switch stuck open replaced pressure switch still getting 3 flashes wich means pressure switch stuck open !! We sell furnace parts, air conditioning parts, AprilAire filters, EZ Flex filters, and many other HVAC parts and supplies at affordable prices. After all this, the furnace … We are Accredited Better Business Members with an A+ Rating! replaced circuit board white rodgers 50a50-241 inducer motor comes on then get 3 fl … read more I am getting a 3 to 1 LED code indicating pressure problems. Also, the drain for a 90% efficient furnace has to be trapped/drained separately from an A/C condensate drain. Test with a voltmeter set again to “Volts AC” and see if the draft inducer is getting between 110 to 125 volts. If the switch is open, the inducer starts and the resulting pressure change closes the switch. So, if you can offer any help please do! Reconnect the wires to the pressure switch. I don’t believe that is the problem. The switch activates with air force pushing a plunger in the mechanism, which closes the circuit. Thanks Steve! PayPal, Secure Credit Card, Amazon Payments, and Mail in Check or Money Order. But if the vent pipe gets blocked or if certain parts in the system fail, then the pressure switch recognizes that there is no longer the proper negative pressure, and it turns on (closes the circuit) to stop the operation of the furnace. Required fields are marked *. The Spruce uses cookies to provide you with a great user experience. Fixing this usually proves to be easy and inexpensive. Just make sure that you have 120 volts coming into the control board between L1 and a neutral (white wire). Reinstall the hose(s). Only 3 left in stock - order soon. If a flue cap is damaged or is damaged where it blocks the flue exit, the switch can open. It would be best if you could test the voltage with the ignitor load hooked up in the circuit. We have had repeated issues with the furnace running for 2-3 minutes, stopping, recycling, and coming back on until the desired temp is reached. But I seem to be out of options with my furnace here. And I have also cleaned the flame sensor with a newspaper (no steel wool). Our email is. Make sure the hose is not obstructed inside. Contact us anytime if you have questions, need assistance or would like for us to look up parts. You would need to turn the thermostat up so that the heat is on and the draft inducer is on. Seems clean. ?… it’s “buggy” as I describe it. If you need parts please send me your furnace’s product number. Arnold’s Service Company, Inc. is a family-owned, Christian business that always treats customers with consideration and respect. Inspect the ventilation slots on the furnace cover to make sure they are clear of debris. When your furnace is in use, gases are created in the combustion chamber. Steve. How do I check to find out the control board is the problem? Please make sure you are getting 24 to 28 volts AC between the W and C (common) terminals from the thermostat when you have the thermostat calling for heat. But I have cleaned the water trap multiple times and there seems to be no issue. I hope you can find and fix the problem. If all your safety controls are closed as you said and your hot surface ignitor is not glowing then it has to either be a control board problem or an ignitor problem. A pressure switch that fails to turn on could be caused by a number of problems, including: The furnace pressure switch can use a different design depending on the type of furnace: Turn off the power to the furnace by switching off the disconnect switch located near the furnace. I would suggest that you do the testing that I described in the earlier post with a volt-meter to determine if you need a new control board or a new draft inducer. During combustion, the combustion blower creates an air pressure that is less than atmospheric (negative pressure) between the inlet side of the combustion blower and the inside of the burner box of the furnace. https://arnoldservice.com/problem-i-have-a-bad-igniter-is-there-anyway-to-light-a-gas-furnace-manually/ I hope you can easily find and fix the problem. I have an Aire-flo furnace 92AF. We Provide Fast UPS Shipping! I remember one furnace I installed where I tried to use 2″ PVC for the venting and ended up having trouble with the pressure switch going off like your furnace is doing. If the reading is higher, the switch has failed and must be replaced by a qualified technician. If you think you have a bad pressure switch Please click here to see the furnace pressure switches we sell. 14 years old and I have never ever had any problems until now any recommendations ? Cleveland is about to have sub-zero Temps coming up this weekend! 4.6 out of 5 stars 66. The installation instructions on these high-efficiency furnaces tell how many feet of the vent pipe is allowed for venting. (4) a dirty or stopped updraft inducer. The pressure switch senses a pressure change and closes a switch to signal the control board that the furnace has proper air flow. Sometimes this will occur 3-4 times depending on reaching the desired temp in the home. Chris. Reduce drafts in the area and examine the pressure tubing. And offered to replace it for another 150$(!). If the pressure switch is closed then you must have another problem that is causing the furnace not to work. I would like to suggest that you use a voltmeter to see if the pressure is actually stuck open. If water is building up inside your pressure switch I would recommend disconnecting the pressure switch tube from the pressure switch so it does not get damaged and use a wet vac to make sure the drain on your condensing furnace is not stopped up. Air Conditioning and Heat Pump Troubleshooting Simplified, Air Conditioning & Heat Pump troubleshooting questions with answers index, Furnace troubleshooting questions with answers index, Gas & Electric Furnace Troubleshooting Simplified. With a smart gas valve that flashes code 3 (low pressure switch stuck open) I have replaced the switches cleaned the furnace and inducer motor is spotless. If you are looking for an HVAC products supplier that will treat you the way you should be treated, turn to us. We have a good post with two YouTube videos on the following page: https://arnoldservice.com/how-to-troubleshoot-and-test-furnace-hot-surface-ignitors-videos/ I would like to suggest that you test to make sure that the ignitor is getting 120 volts AC during the ignitor glow phase of the ignition cycle. The inducer motor starts, the ignitor glows, gas goes out from the the valve, fires up, blower works, then a few mins later, the inducer motor shuts off, the red light blinks 3 times, which means open pressure switch…. I hope you have a blessed day. If there is no disconnect switch, turn off the furnace's breaker in the home's service panel (breaker box). Answer: Hi! If not, positive fan pressure can sneak through the furnace drain and create uneven pressure for the pressure switch. Problem: Hello, love the website and help that it offers. After worked sometimes 3 mins, sometimes 10 mins, the inducer motor shut off always. Tested inducer motor capacitor with a meter, all good. If all your safety controls are closed like the pressure switch, limit, rollouts and if you are not getting 120 volts to the ignitor then it almost has to be a control board problem. If your draft inducer has a capacitor make sure the capacitor is in good condition. And offered to replace it for another 150$(!). God bless you. A pressure switch error on a Trane furnace may lead to a very cold home if not corrected in a timely manner. If the control board is correct in saying and showing that the pressure switch is the problem… then I would suggest looking at the things like you have already have, like the condensate trap and drain lines from the secondary heat exchanger. That means the low stage pressure switch is stuck open, meaning the pressure switch is not closing when the exhaust fan is coming on. So you need to check and make sure the exhaust fan comes on first. Managed by Wooassist - Woocommerce Support www.wooassist.com. This is not a repair. I hope that it fixes the problem. Hi Dan! Cleveland is about to have sub-zero Temps coming up this weekend! Kelly Bacon is a licensed general contractor with almost 50 years experience in construction, home building and remodeling, and commercial building. But I have cleaned the water trap multiple times and there seems to be no issue. We have a really good YouTube Video made by AC Service Tech, below that shows how to properly clean out a furnace’s condensate drain lines and trap. If the inducer is not getting 120 volts then you have control board problem. Remove the pressure switch hose(s) after carefully noting where it is connected (if there is more than one hose, remove and reinstall them one at a time). If the switch does not close, after approx 1 minute, the IFC goes into lockout mode. Nor is intake. (6) someone has sucked on the pressure switch with their mouth or forgot to unhook the pressure switch from the furnace before using a vac on the furnace. You should be able to light your furnace manually if your family is really cold. If the switch is open, the inducer starts and the resulting pressure change closes the switch. Introducing "One Thing": A New Video Series, Electrical failure of the pressure switch. New batteries for the thermostat. This hole in the heat exchanger will not allow the negative pressure that the pressure switch needs to close and operate properly. I didn’t perform the pressure test on the switch, but I did confirm that it closes when the inducer turns on. We have a really good YouTube Video made by, I hope you can find and fix the problem. Please click here if you would like to see our Gas Furnace Troubleshooting Flow Chart. I have a Nordyne updraft furnace with a Pressure Switch Open Fault, according to the troubleshooting chart. Other times it works just fine…? Only OEM pressure switches should be used. 95. The pressure switch should be considered the indicator of the problem, not the problem. Hello I have a Heil mid efficient furnace. Also make sure the control board is sending 120 volts to the draft inducer when the thermostat is calling for heat. Do you think I have issue with control board? No water lines to or from being blocked. replaced circuit board white rodgers 50a50-241 inducer motor comes on then get 3 flashes !!! Still have a problem? Remove debris with a small screwdriver or similar tool, being careful not to poke into the switch body. When I called a technician he came out and charged 170$ just to tell me my pressure switch was broken. If this solves the problem do not trust the switch not to fail again. Get daily tips and tricks for making your best home. When you do this, you should hear a clicking noise. If you ever experience a problem with any of your orders, contact us right away and we will make it right. I replaced one of my pressure switches, the one connected to inducer motor, then the furnace fired up. Tapping lightly on the pressure switch body may open the switch and the unit may start. Sometimes controls boards with show 120 volt when the ignitor is not hooked up, but when the ignitor is hooked up the voltage will go to zero or really low. If the pressure switch will not close as the board is flashing then you have found the problem. I am getting a 3 to 1 LED code indicating pressure problems. A bad switch, or a tripped switch, is a common cause of furnace malfunctions. What Is a High-Temperature Limit Switch on a Furnace? We carry a huge range of brand name items that can be purchased online. If you can hold the 4 wire connector in the right place many times the valve will work. The low-pressure switch should close and provide 24 volts AC between each of the two terminals on the pressure switch to a good ground. When I called a technician he came out and charged 170$ just to tell me my pressure switch was broken. The control board your furnace uses is a PCBBF112S like we sell on the following page: https://arnoldservice.com/product/goodman-amana-furnace-control-board-pcbbf112s/ The inducer part number is a 22307501S which has been updated to part number 0171M00000S. Your email address will not be published. The exhaust is not blocked leading outside. I measured continuity with the furnace off (switch open), then got continuity when the inducer started. Bob Formisano is a licensed architect and builder with 30 years of experience in the industry. Remove the main access panel on the front of the furnace. If you are getting a constant 24 to 28 volts AC to the furnace all the time between W and C when the furnace cuts off then this would eliminate the thermostat from being the problem. If the ignitor is not getting 120 volts AC when it is supposed to be glowing then it is a control board problem. The contacts in the switch are either stuck together or moisture has entered the switched and seized it in the closed position. We have a furnace troubleshooting flow chart that I hope will help you out on the following page: Please click here if you would like to see our Gas Furnace Troubleshooting Flow Chart. Hi Ms. Jackson! Clean the vents, if necessary. Replaced both pressure switches . Ventless Gas Fireplaces: What to Know Before You Buy, A Short Guide to a Furnace Pressure Switch, 3 Things to Check When Your Furnace Stops Working, How to Replace a Furnace Thermocouple or Electronic Flame Sensor, How to Troubleshoot a Gas Furnace That Produces No Heat, Troubleshooting an Electronic Ignition Furnace That Won't Light, How to Maintain a Furnace-Mounted Whole-House Humidifier, Easy Winter Preparation Checklist for Your Home, A Visual Guide to a High-Efficiency Condensing Furnaces, How to Check a Pilot Light on a Gas Furnace, How to Wire and Install Single-Pole Switches. Some other things that cause furnace pressure switch problems are: (1) A restricted vent pipe (2) Too long of vent piping and too many turns which exceeds manufacturer’s recommendations (3) a stopped-up condensate drain line if you have a high efficiency condensing furnace. If you have exceeded the number of turns the furnace will not run right and the pressure switch will not work or stay closed. Please advise. 20197308 - Goodman OEM Furnace Replacement Air Pressure Switch. It doesn't take much pressure, so don't blow too hard. In the case of a light switch, no lights will come on until you flip the switch by hand and allow power to the light but your pressure switch is activated by air pressure or in this case suction. If your thermostat uses batteries please make sure they are in good shape. I hope you get it fixed soon! The hole where the pressure switch attaches to the draft inducer could be stopped up with water, slug, or dirty. Clean and I still get the same code what could be the problem the furnace is. Take off the end so you can blow through it to the pressure switch. It's a good idea to check the air intake, flue piping and outdoor exhaust vent for blockages each time the furnace registers an open or closed pressure switch error. Without the pressure switch, there is the potential for exhaust gases to fill the living space if the furnace malfunctions. Sorry to hear that you are having problems with your furnace. Thanks for any help. It is designed to sense the negative pressure created by the draft inducer motor during the furnace startup and to shut down the furnace ignition if the air pressure isn't sufficient for removing the exhaust fumes. I ordered one myself and replaced it last weekend. Hi Mr. Rankin! I hope you can easily find and fix the problem. But, I’m still having the same symptoms. We would love to have your business! Restricted airflow can also cause the furnace pressure switch to malfunction. I checked and no 120v go into the ignitor. Whether you need furnace ignitors, AprilAire filters, EZ Flex filters, or another kind of HVAC merchandise, we want to serve you. Testing the switch itself requires a multimeter. No residue on it. Turn Off the Power Turn off the power to the furnace by switching off the disconnect switch … Nor is intake. The pressure switch on a furnace may fail or get stuck in an open position, and there are few simple checks you can complete before testing the switch for electrical failure. The source of pressure switch problems can sometimes be a pain to track down. Rollout and limit switches are good (I jumped to test them), cleaned all I can. Hi Steve, Do not blow into the inlet to remove the obstruction. Steve, Your email address will not be published. And again the pressure switch is brand new (supposedly). Turn off and unplug the furnace. Problem: Furnace blink code shows I have a pressure switch problem. The venting is critical for these high-efficiency furnaces to run right, to say the least! The tester should read 0 or close to 0 (indicating no resistance). If the switch stays open the furnace will not turn on since it thinks the inducer motor has not turned on. If the inducer motor will not come on it could be the thermostat not allowing the furnace to start. Check the vent pipe for blockage, if the furnace is a condensing type. Detach the pressure switch hose from the induced draft blower and pressure switch component. I would like to suggest that you use a voltmeter to see if the pressure is actually stuck open. ?… it’s “buggy” as I describe it. Yes, if the draft inducer goes off in the middle of the heating cycle then you will get the “Open Pressure Switch” fault. Please click here to see the furnace pressure switches we sel, https://arnoldservice.com/how-to-troubleshoot-and-test-furnace-hot-surface-ignitors-videos/, https://arnoldservice.com/problem-i-have-a-bad-igniter-is-there-anyway-to-light-a-gas-furnace-manually/, https://arnoldservice.com/how-to-test-and-troubleshoot-gas-furnace-pressure-switches/, https://arnoldservice.com/honeywell-smart-valve-ignitor-flame-sensor-troubleshooting/, https://arnoldservice.com/product/goodman-amana-furnace-control-board-pcbbf112s/, https://arnoldservice.com/product/0171m00001s-goodman-furnace-draft-inducer/, American Standard Trane Condenser Fan Motors, ICP Heil Tempstar Whirlpool Flame Sensors, Trane American Standard Furnace Draft Inducers, Trane American Standard Pressure Switches, Managed by Wooassist - Woocommerce Support. Here is a link to that page if you want to try and light your furnace manually. We have a troubleshooting Honeywell Smart Valve page that I hope will help: https://arnoldservice.com/honeywell-smart-valve-ignitor-flame-sensor-troubleshooting/ I have seen these Smart Gas valves cause lots of problems.