Tomas. Posted April 26, 2018 Share Posted April 26, 2018 Hey guys. I am having an issue with my furnace and I am running out of ideas. The pilot light went out this morning and I have it lit again. The pilot light stays on but the main burners will not turn on. The induction motor runs. I changed the thermocouple but still no luck. Anyone have any ideas? It is a Nordyne M1GH 090A AW. Quote Link to comment Share on other sites More sharing options...
f7ben Posted April 26, 2018 Share Posted April 26, 2018 1 minute ago, Tomas. said: Hey guys. I am having an issue with my furnace and I am running out of ideas. The pilot light went out this morning and I have it lit again. The pilot light stays on but the main burners will not turn on. The induction motor runs. I changed the thermocouple but still no luck. Anyone have any ideas? It is a Nordyne M1GH 090A AW. flow switch Quote Link to comment Share on other sites More sharing options...
f7ben Posted April 26, 2018 Share Posted April 26, 2018 there is a print on the inside of the door panel ........in the print it will show 3-4 things that will prevent it from working.... thermocouple , flow switch...sometimes a pressure switch. You need to get a meter and check the circuit or just change the common parts Quote Link to comment Share on other sites More sharing options...
Tomas. Posted April 26, 2018 Author Share Posted April 26, 2018 4 minutes ago, f7ben said: flow switch I am not seeing a flow switch Quote Link to comment Share on other sites More sharing options...
f7ben Posted April 26, 2018 Share Posted April 26, 2018 check that over temp switch....I have never seen a furnace without a flow switch and I gaurantee it has one Quote Link to comment Share on other sites More sharing options...
Tomas. Posted April 26, 2018 Author Share Posted April 26, 2018 when I unplug a limit switch I hear the gas valve click, they appear to be working. Quote Link to comment Share on other sites More sharing options...
f7ben Posted April 26, 2018 Share Posted April 26, 2018 5 minutes ago, Tomas. said: when I unplug a limit switch I hear the gas valve click, they appear to be working. do you have a meter? multimeter? Quote Link to comment Share on other sites More sharing options...
AKIQPilot Posted April 26, 2018 Share Posted April 26, 2018 Check the pressure switch. That is the final step to tell the gas valve to open. Quote Link to comment Share on other sites More sharing options...
Tomas. Posted April 26, 2018 Author Share Posted April 26, 2018 Just now, f7ben said: do you have a meter? multimeter? Quote Link to comment Share on other sites More sharing options...
f7ben Posted April 26, 2018 Share Posted April 26, 2018 find each switch and check voltage across it......you will find what is open and preventing the furnace from working Quote Link to comment Share on other sites More sharing options...
Tomas. Posted April 26, 2018 Author Share Posted April 26, 2018 (edited) I am a little niave when it comes to electrical, especially when dealing with a house. I have never done it before. At the risk of sounding retarded, how would be go about doing that? Edited April 26, 2018 by Tomas. Quote Link to comment Share on other sites More sharing options...
AKIQPilot Posted April 26, 2018 Share Posted April 26, 2018 1 minute ago, Tomas. said: I am a little niave when it comes to electrical, especially when dealing with a house. I have never done it before. At the risk of sounding retarded, how would be go about doing that? Set your meter to continuity. Ohms of resistance. Some components in your furnace are normally closed so there will be very little reaistance when they are satisfied. When they reach their limit they open and stop current from passing to the end device. When they go open the reaistance will show OL or Open or something other than a number on the meter. Other components need to be satisfied for the furnace to continue to the fire mode. These components are normally open and will show OL or Open when reading their unsatisfied state. When satisfied they will show a small amount of resistance. The pressure switch should show OL or Open when the furnace isnt running. It will have less than .010 ohms of resistance when it is satisfied a high limit switch will have less than .010 ohms of reaistance when the furnace isnt running if the hi limit switch reaches its hi temp limit ot will open and show OL Quote Link to comment Share on other sites More sharing options...
AKIQPilot Posted April 26, 2018 Share Posted April 26, 2018 After setting your meter to ohms touch the leads together. That is basically zero reaistance. Next pull the leads apart. That reading will show that the circuit is open and not passing current through it. Quote Link to comment Share on other sites More sharing options...
Tomas. Posted April 26, 2018 Author Share Posted April 26, 2018 Thank you very much!!! The pressure switch when induction motor is off reads 1719 and when the motor is on it reads 0 Quote Link to comment Share on other sites More sharing options...
AKIQPilot Posted April 26, 2018 Share Posted April 26, 2018 (edited) What does the meter read when the leads arent touching anything. Edited April 26, 2018 by AKIQPilot Quote Link to comment Share on other sites More sharing options...
f7ben Posted April 26, 2018 Share Posted April 26, 2018 I'm too drunk for this right now Quote Link to comment Share on other sites More sharing options...
AKIQPilot Posted April 26, 2018 Share Posted April 26, 2018 I would click your meter to 20k ohms of reaistance. Or something in that area of the meter. Quote Link to comment Share on other sites More sharing options...
f7ben Posted April 26, 2018 Share Posted April 26, 2018 Just now, AKIQPilot said: I would click your meter to 20k ohms of reaistance. Or something in that area of the meter. I prefer to check voltage when troubleshooting circuits like this......its easier to find the issue Quote Link to comment Share on other sites More sharing options...
Gold Member BOHICA Posted April 26, 2018 Gold Member Share Posted April 26, 2018 (edited) does the propane tank have propane in it? Edited April 26, 2018 by BOHICA Quote Link to comment Share on other sites More sharing options...
f7ben Posted April 26, 2018 Share Posted April 26, 2018 Just now, BOHICA said: does the propane tank have fuel in it? pressure switch will tell him that Quote Link to comment Share on other sites More sharing options...
Tomas. Posted April 26, 2018 Author Share Posted April 26, 2018 1 minute ago, AKIQPilot said: What does the meter read when the leads arent touching anything. Quote Link to comment Share on other sites More sharing options...
Tomas. Posted April 26, 2018 Author Share Posted April 26, 2018 It is natural gas. Quote Link to comment Share on other sites More sharing options...
AKIQPilot Posted April 26, 2018 Share Posted April 26, 2018 (edited) 4 minutes ago, f7ben said: I prefer to check voltage when troubleshooting circuits like this......its easier to find the issue Probably true. But some of these circuits are AC and some DC. So he will have to click back and forth to see which component is functioning properly. If he checks an ac source while the meter is set to dc he could damage it or blow its fuse or breaker. I meant to say, some are high voltage and some are 24volts. Im no expert by a long shot but I periodically have to troubleshoot my boiler. Similar process. Edited April 26, 2018 by AKIQPilot Quote Link to comment Share on other sites More sharing options...
AKIQPilot Posted April 26, 2018 Share Posted April 26, 2018 1 minute ago, Tomas. said: Perfect. That is an open circuit. Electric signal doesnt pass through open circuits. I think you need to select a different position in the ohms Quote Link to comment Share on other sites More sharing options...
Gold Member BOHICA Posted April 26, 2018 Gold Member Share Posted April 26, 2018 Burner doesnt light at all? is it a new enough unit to have any diagnostic lights flashing? Quote Link to comment Share on other sites More sharing options...
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