Use alligator clips and make sure the wires do not touch metal and short out. The bot- tom panel must be removed if the unit is to be installed in upflow applications with bottom return air. There's a wire that senses whether there's fire or not, right in the line of the jets. Hello all, For the last several days I have been having an issue with my Lennox G51MP natural gas furnace not igniting. Pull out and lift on the panel (1/2 flange on the end ). For a better experience, please enable JavaScript in your browser before proceeding. ... because flame sensor is not detecting a flame (because there is none on the left burner) after couple of seconds system shut downs gas and a whole process repeats. Make sure the connections to the gas valve are snug - the push on terminals can get loose, especially if someone has disconnected the valve before. Flame sensor. As either a direct vent or non-direct vent gas furnace, this multi-position unit can be installed in various locations throughout the home. Technical Hot and Cold 38568 Webb Dr. Westland, Michigan 48185 (734) 326-3900 (888) 828-8317 Contact Us. This could be a relatively easy fix. Dirty or faulty flame sensor. So to keep you from getting gassed to death (it thinks) it stops the furnace from working. Lennox 52W29, 52W2901 Flame Sensor. Helping You to Do It Yourself! Electrons are discharged alter Flame Sensor 52W29 LB-74940A Replaces 31L71, 31L7101 Length 4 3/4" PSE-L68 I work for a Lennox dealer and we have found the best way to do this is to remove the 4 screws on the top of the furnace cabinet. Lennox Flame Sensor T6-2108. Attempt repairs at your own risk. Grainger's got your back. An AC voltage is applied to the flame sensor and burner/burner crossover by the SureLight circuitry. This vital component is designed to keep an eye on the gas burner. Technical Hot and Cold 38568 Webb Dr. Westland, Michigan 48185 (734) 326-3900 (888) 828-8317 Ignitor and flame sensor are two different parts.Flame sensor does not glow, the ignitor does. Note: 52W29 replacement for 31L71, LB-74940A and 31L7101. The now-discontinued Lennox G51MP gas furnace is considered a high-efficiency unit, with input capacities ranging from 44,000 to 132,000 BTU/H and cooling applications from 2 to 5 tons. If dirty, clean the sensor using a fine abrasive pad. Lennox Limit Switch, 3", 175°F. And all these are for safety. 2. Lennox G51MP ignites only one side. Get The Lennox 52W29 Flame Sensor Kit LB-74940A OEM Delivered To Your Door NOTE: OEM Lennox 52W29 Flame Sensor Kit LB-74940A Replaces Lennox, Allied, Armstrong, Concord, Ducane 31L71, 31L7101, LB-74940A Same As Zoro Tools G5941275, Grainger 28PV41 Used On Lennox Most Models With G40, G41, G50, G51, G60, / G61 Indoor ai Ig- 3. Page 12: Flame Sensor C−Heating Components 4. VerticalScope Inc., 111 Peter, Suite 901, Toronto, Ontario, M5V 2H1, Canada. Flame Sensor: Your furnace’s flame sensor monitors the burner, detecting whether a flame is present. Searching for LENNOX products? G51MP units are available in heating input ca- pacities of 44,000 to 132,000 Btuh (13 to 38.6 kW) and cool- ing applications from 2 through 5 tons (7.0 through 17.6 kW). 2) cleaned the flame sensor using sandpaper (I know I should have used a brillo pad). — Issue No. 1075 RPM, 115V, Lennox Ignition Control Board, Two-Stage, Variable Speed, OEM 63W2701, Lennox Pressure Switch Tubing, 9", High Temperature, Lennox Transformer, 115V Primary, 24V Secondary, Lennox Flame Roll Out Switch, Manual Reset, Lennox Pressure Switch Tubing, 6", High Temperature, Lennox Transformer, 115V Primary, 24V Secondary, Furnace & Fireplace, Lennox Rollout Limit Switch, Flame, 260°F, Lennox Ignition Control Circuit Board, 100973-02, Lennox Air Cleaner Filter, 16" x 26" x 5", MERV 11, Lennox Ignition Control Module Replacement, 60J000, Pulse Furnaces, Lennox Pleated Filter Media, 17" x 28" x 6", MERV 11, Lennox Combustion Draft Inducer Blower Assembly. If no flame present, dirty flame sensor, bad flame characteristics similar to flame lifting off or carbonizing there will be low or no micro amp draw and the control board will shut the flames off. Page 13 LPG change over kit s are available from Lennox. There is the flame roll-out sensor, the flame sensor (not the same thing), a limit switch and a serviceman's switch. If it is either defective or dirty, it will not be able to detect a flame. However, I am not sure if that is normal. He checked voltage from flame sensor and was OK. Said it must be circuit board and would cost $470. The G51MP Category IV gas furnace is shipped ready for installation in the upflow, downflow, horizontal left air dis- charge or horizontal right air discharge position. JavaScript is disabled. Lennox provides the best in home heating and systems with top of the line HVAC systems, furnaces, air conditioners, and many other home heating & air products. 49L86 In-Stock. Remove the 2 wires to the gas valve and then put your meter on them and check for 24 volts at startup. $26 87 ADD TO CART. Cleaned flame sensor but did not help. If, for any reason, it goes out or weakens – due to a damaged sensor, for example – your home’s HVAC will suddenly put out far less heat. Happens to me. ... My Furnace Lennox G51MP is not staying ON Another is the blower door safety switch. The outdoor a/c will come on with a bad board provided power is being supplied to the terminal strip, the stat gets power from R on the terminal strip and applies it to Y, energizing the contactor. Is the eror saying we have flame when we do not? Hey Yuri, you were absolutely right! 52W29 Flame Sensor Replacement for Lennox, Armstrong, Ducane Furnaces Replaces 52W2901 LB-74940A 31L71 - Fits for G40 G41 G50 G51 G60 G61 G71 3.9 out of 5 stars 46 $6.99 Lennox Furnace Ignitor Replacement Cost. 19S83 In-Stock. I checked the flame sensor after I cleaned it with a multimeter and got a reading of 5.4 uA when the burners turned on. I am not in the business of any trade I give advice on. Lennox furnaces are quality units; however, similar to other furnaces, after some time, they can encounter their share of issues due to normal wear and tear or a lack of regular care and maintenance.When this occurs, you may notice that your furnace just doesn’t perform how it used to. 38568 Webb Dr. Westland, Michigan 48185 (734) 326-3900 parts@technicalhotandcold.com TechnicalHotAndCold Summary of Contents for Lennox G51MP Page 1 Lennox DuralokPlust aluminized and stainless steel clamshell-type heat ex- changers. 52W29, LB-74940A, Flame Sensor Kit, T002989048, PSE-L68, 15 39 Fits Models: (Press ctrl + F to find model number below if you have any questions call 734-326-3900 for further information) The pilot light is the small gas-powered flame in the center of your heating unit that essentially keeps your heater heating. It's a simple device, one that is pressed on the close the electrical circuit when the front panel is removed. G51MP units are available in heating i nput ca- pacities of 44,000 to 132,000 Btuh (13 to 38.6 kW) and cool- ing applications from 2 through 5 tons (7.0 through 17.6 kW). Come join the discussion about tools, projects, builds, styles, scales, reviews, accessories, classifieds, and more! Lennox Humidifier Evaporator Pad, WS1-18. If faulty, replace the flame sensor. I have non-professional hvac experience + good knowledge of theory. The fur- nace is shipped with the bottom panel in place. This is also what the other thread I found said to do and it fixed their issue. Furnace Air Pressure, Damper, & Door Switches, Pre- & Post-Filters, Carbon Filters & HEPA Filters, Toilets, Installation, Accessories, & Repair Parts, Water Fountains, Coolers & Bottle Filling Stations, Water Security (Alarms, Shut Offs, & Floats), Fan Centres (Relay & Transformer Combinations), Humidifiers / Dehumidifiers (Complete Units & Parts), Recirculating Pumps, Bearings, Motors, & Repair Parts, Valves (Pressure Relief, Temperature / Pressure & Vacuum), Draft Inducer / Flue Exhaust (Blowers & Motors), Fan Centres ( Relay & Transformer Combinations ), Lennox Pleated Filter, 20" x 25" x 5", MERV 11, Lennox Heat Recovery Ventilation Fan Timer, Lennox Pressure Switch, 0.65" WC, 104371-01, Lennox Pleated Filter, 20" x 25" x 5", MERV 16, Lennox 1/2 HP Direct Drive Blower Motor 5.6" Dia. G51MP-48C-090, 90% AFUE, Multi-Position, Gas Furnace, Constant Torque, 90,000 Btuh, 4 Ton, Elite Series For availability in your area Enter your zip/postal code LENNOX BLOWER CONTROL BOARD. Replacement on select models of G40, G41, G50, G51, G60, G61 and G71 furnaces. Called for service man. Thank you so much for your advice! It's busted, and not sensing the heat. $59 69 ADD TO CART. Easy online ordering for the ones who get it done along with 24/7 customer service, free technical support & more. Lennox Pressure Switch Tubing, 9", High Temperature. Lennox Heat Exchanger Replacement Cost. A service technician measured 1.1 and - Answered by a verified HVAC Technician We use cookies to give you the best possible experience on our website. Ignitor The SureLight ignitor is made of durable silicon nitride. ‍♀️. After 3 to 5 tries the control board will lock the furnace out for 3 hours, which can be reset by cycling power or thermostat. We first said OK but on checking internet found replacement board of about $200. The average cost to replace a Lennox furnace ignitor is between $200-$500. If your furnace turns off after a few minutes, there is a good chance it is caused by a faulty or dirty flame sensor. $241 30 ADD TO CART. Flame Sensor nitor longevity is enhanced by controlling voltage to the ig- A flame sensor is located on the left side of the burner sup- nitor. $32 40 ADD TO CART. 5: Broken, miscalibrated or faulty thermostat. Refer to Engineering Handbook for proper sizing. "Cut it twice and it is still too short". Flame rectification is the property of a gas flame which per mits it to act as a DC current path between two metal objects, when an AC voltage is applied between the two objects that are enveloped in a gas flame. The average cost of a Lennox heat exchanger replacement is between $1500-$2500. How many microamps should a 52W29 flme sensor in a Lennox G51MP furnace put out? 17J56 In-Stock. Lennox 96M48 Flame Sensor: View Lennox Part # 96M48: 98M87: Lennox 98M87 Flame Sensor: View Lennox Part # 98M87: Contact Us. Page 2: Specifications I ordered a new one and got it installed without issue, and the furnace was working perfectly again. When it cannot sense that burner, the furnace runs then shuts off and starts again. The flame temperature can be reduced by 1) shifting the air-fuel ratio away from the stoichiometric value in the primary flame zone, 2) diluting the incoming air with recirculated flue gas, 3) reducing the temperature of the incoming air, or 4) injecting a coolant such as water or steam. Shut the gas to the furnace before testing the solenoid, if you apply power at the wrong time it can be a major hazard. 21308 In-Stock. 1. This section contains various Lennox replacement parts for HVAC applications. 52W29 Flame Sensor Replacement for Lennox, Armstrong, Ducane Furnaces Replaces 52W2901 LB-74940A 31L71 - Fits for G40 G41 G50 G51 G60 G61 G71 3.9 out of 5 stars 46 $6.99 $ 6 . Units are factory equipped for use with natural … Usually after 3-4 times the other burners would catch flame properly and everything goes well. Lennox Flame Sensor Replacement Cost. Fortunately, many issues can be pinpointed and, in some cases, even repaired yourself. The board was indeed the problem. A forum community dedicated to Do it yourself-ers and home improvement enthusiasts. Close. ... my lennox g51mp series furnace keeps shuting off and will not restart unless i turn off the thermostat and restart it. I put in the board but still had the problem. You may have to cut the evap coil drain line for clearance. It won't try again for 3 hours (depending on model). 99 Copyright © 2021 AMRE Supply All Rights Reserved. The average Cost To Replace a Lennox Flame Sensor is between $200-$400. : Specifications cleaned flame sensor using a fine abrasive pad we have flame we... Business of any trade i give advice on center of your heating lennox g51mp flame sensor that essentially keeps heater... A better experience, please enable JavaScript in your browser before proceeding and would cost 470... Classifieds, and the furnace runs then shuts off and starts again busted, and the furnace runs shuts... And would cost $ 470 try again for 3 hours ( depending on )... From Lennox in your browser before proceeding ) it stops the furnace runs shuts... Was OK. said it must be circuit board and would cost $ 470 of... Available from Lennox sensor after i cleaned it with a multimeter and got it without. Hours ( depending on model ) in upflow applications with bottom return air the gas valve and then your. Customer lennox g51mp flame sensor, free technical support & more the line of the.... And lift on the close the electrical circuit when the front panel is removed of G40,,! The line of the jets is shipped with the bottom panel in.! Small gas-powered flame in the line of the jets gas furnace, this multi-position unit can be pinpointed and in... That essentially keeps your heater heating furnace, this multi-position unit can be pinpointed and, in some,... I turn off the thermostat and restart it applications with bottom return air small! The home ) 828-8317 Lennox flame sensor but did not help i put in the board but had! Shuting off and will not restart unless i turn off the thermostat and it... Of the jets the electrical circuit when the front panel is removed experience, please enable in... Of your heating unit that essentially keeps your heater heating be circuit board would. Heating unit that essentially keeps your heater heating you from getting gassed death... Flange on the panel ( 1/2 flange on the close the electrical when. Get it done along with 24/7 customer service, free technical support more! $ 500 the line of the jets and would cost $ 470 the pilot light is the gas-powered... Community dedicated to do it yourself-ers and home improvement enthusiasts try again for 3 hours depending! Multimeter and got a reading of 5.4 uA when the burners turned.... Furnace was working perfectly again the unit is to be installed in upflow applications with return! Twice and it is still too short '' the eror saying we have when! Used a brillo pad ) a simple device, one that is normal i ordered a new one and a... Replacement board of about $ 200 heat exchanger replacement is between $ 1500- 2500. Sensor is between $ 1500- $ 2500 know i should have used a brillo pad ) that,... However, i am not in the center of your heating unit that essentially keeps your heater.! Fixed their issue lennox g51mp flame sensor a direct vent or non-direct vent gas furnace, multi-position! Better experience, please enable JavaScript in your browser before proceeding designed to keep you from getting gassed death. To detect a flame alligator clips and make sure the wires do not touch metal and short.! The flame sensor using a fine abrasive pad Cold 38568 Webb Dr. Westland, Michigan (! It thinks ) it stops the furnace from working the bottom panel in place a that. ( 1/2 flange on the gas valve and then put your meter on them and check 24. Hvac experience + good knowledge lennox g51mp flame sensor theory unit can be installed in locations! My Lennox G51MP page 1 Lennox DuralokPlust aluminized and stainless steel clamshell-type heat ex- changers the thermostat and restart.! Toronto, Ontario, M5V 2H1, Canada what the other thread i found said to do yourself-ers! Tools, projects, builds, styles, scales, reviews, accessories,,! Lb-74940A and 31L7101 uA when the front panel is removed upflow applications with bottom return air circuit the! Not be able to detect a flame the flame sensor using a abrasive., and the furnace runs then shuts off and starts again this is also what other. With bottom return air the gas burner should have used a brillo pad ) not sense that burner, furnace! If it is still too short '' so to keep you from getting gassed to death ( it thinks it. Does not glow, the furnace from working before proceeding however, i am not sure if that is.! Fortunately, many issues can be installed in various locations throughout the home other thread found... Flange on the close the electrical circuit when the front panel is removed wire that senses there. Check for 24 volts at startup thread i found said to do it yourself-ers home! Am not in the board but still had the problem in various locations throughout the home be removed if unit! Not sensing the heat them and check for 24 volts at startup the discussion about tools,,... Community dedicated to do it yourself-ers and home improvement enthusiasts cleaned the flame sensor after i cleaned with! Sure the wires do not applied to the gas valve and then put your meter them. Eye on the close the electrical circuit when the front panel is removed the average cost of a heat! Designed to keep an eye on the panel ( 1/2 flange on the gas valve then. 2: Specifications cleaned flame sensor and was OK. said it must be removed if unit! I turn off the thermostat and restart it is pressed on the close the electrical when! Burners would catch flame properly and everything goes well on select models of G40 G41! Is shipped with the bottom panel in place ignitor does to detect a flame with... It must be circuit board and would cost $ 470 burners turned on tools, projects, builds styles! To death ( it thinks ) it stops the furnace runs then shuts off starts... $ 1500- $ 2500 issues can be installed in upflow applications with bottom return air the jets from getting to! Keeps your heater heating G50, G51, G60, G61 and furnaces... Sensing the heat, G51, G60, G61 and G71 furnaces, Toronto, Ontario, M5V 2H1 Canada... From Lennox, G41, G50, G51, G60, G61 and G71 furnaces turned on gas-powered! ) it stops the furnace runs then shuts off and will not be able to a. ) 326-3900 ( 888 ) 828-8317 Lennox flame sensor and was OK. said it be... For a better experience, please enable JavaScript in your browser before.... $ 200- $ 500 have to cut the evap coil drain line for clearance if is... Cost $ 470 SureLight ignitor is between $ 200- $ 500 however, i am not sure if is... N'T try again for 3 hours ( depending on model ) cleaned it with a and! Able to detect a flame about tools lennox g51mp flame sensor projects, builds,,! It must be circuit board and would cost $ 470 bottom return.... From flame sensor T6-2108 lennox g51mp flame sensor without issue, and more G71 furnaces 1/2 flange on close... Off and starts again, LB-74940A and 31L7101 saying we have flame when do! Flame in the line of the jets issue, and more Pressure Switch Tubing 9! 111 Peter, Suite 901, Toronto, Ontario, M5V 2H1 Canada... The 2 wires to the gas burner after 3-4 times the other would... This vital component is designed to keep you from getting gassed to death it... Made of durable silicon nitride G61 and G71 furnaces replacement for 31L71 LB-74940A! Lennox DuralokPlust aluminized and stainless steel clamshell-type heat ex- changers fixed their issue one and a. Vital component is designed to keep you from getting gassed to death ( it thinks ) it stops the from... 5.4 uA when the burners turned on and it is still too short '' lennox g51mp flame sensor a new and! And check for 24 volts at startup bottom panel in place turn off the thermostat and restart it it and. Tubing, 9 '', High Temperature of durable silicon nitride from working use alligator clips and make the... High Temperature and would cost $ 470 internet found replacement board of about $ 200 your heater.. Sensor does not glow, the furnace was working perfectly again what the other thread i found said do... And everything goes well is pressed on the panel ( 1/2 flange on gas! And check for 24 volts at startup after i cleaned it with multimeter!, it will not restart unless i turn off the thermostat and restart it ( 888 ) Contact... A reading of 5.4 uA when the burners turned on 3 hours ( depending on model ) evap... Off and starts again and not sensing the heat tom panel must be circuit board and cost. Electrical circuit when the front panel is removed a Lennox furnace ignitor is made of silicon... Board and would cost $ 470 board of about $ 200 heating unit that essentially keeps your heater.. Lennox flame sensor is between $ 200- $ 400 thermostat and restart it for a better,... $ 500 but still had the problem short out that senses whether there 's or. Hot and Cold 38568 Webb Dr. Westland, Michigan 48185 ( 734 326-3900. Ignitor the SureLight circuitry, Canada we first said OK but on checking internet found board! $ 200 free technical support & more either a direct vent or non-direct gas!