f7ben Posted April 26, 2018 Share Posted April 26, 2018 2 minutes ago, AKIQPilot said: 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. The control circuit is probably all 24v ac and he isnt going to hurt anything with any modern meter checking around. Quote Link to comment Share on other sites More sharing options...
AKIQPilot Posted April 26, 2018 Share Posted April 26, 2018 1 minute ago, f7ben said: The control circuit is probably all 24v ac and he isnt going to hurt anything with any modern meter checking around. Roger that. Quote Link to comment Share on other sites More sharing options...
Tomas. Posted April 26, 2018 Author Share Posted April 26, 2018 Running the meter on 20k the pressure switch reads 1 with the induction motor off and 0 with it on. The hi limit switch reads 0 with it on or off. Aux limit reads the same as the hi limit 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: Roger that. I just made that up.....I have no idea I'm probably the most uneducated electrician in the world 1 Quote Link to comment Share on other sites More sharing options...
f7ben Posted April 26, 2018 Share Posted April 26, 2018 Just now, Tomas. said: Running the meter on 20k the pressure switch reads 1 with the induction motor off and 0 with it on. The hi limit switch reads 0 with it on or off. Aux limit reads the same as the hi limit that means the pressure switch is working and the hi limit is working maybe you have a bad gas valve 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: Running the meter on 20k the pressure switch reads 1 with the induction motor off and 0 with it on. The hi limit switch reads 0 with it on or off. Aux limit reads the same as the hi limit Ok so all those components are functioning like they should. Quote Link to comment Share on other sites More sharing options...
AKIQPilot Posted April 26, 2018 Share Posted April 26, 2018 Just now, f7ben said: that means the pressure switch is working and the hi limit is working maybe you have a bad gas valve Yep. Those components are working correctly. Quote Link to comment Share on other sites More sharing options...
f7ben Posted April 26, 2018 Share Posted April 26, 2018 Is there a small circuit board with a few small led's on it that blink? 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 plugged vent? 1 Quote Link to comment Share on other sites More sharing options...
AKIQPilot Posted April 26, 2018 Share Posted April 26, 2018 3 minutes ago, Tomas. said: Running the meter on 20k the pressure switch reads 1 with the induction motor off and 0 with it on. The hi limit switch reads 0 with it on or off. Aux limit reads the same as the hi limit Keep in mind that when the 1 is to the left of the screen it really isnt a 1. It means the circuit is open and has no resistance. Quote Link to comment Share on other sites More sharing options...
Tomas. Posted April 26, 2018 Author Share Posted April 26, 2018 Gas valve read "1" or open all the time. But I can physically hear and feel it click. No circuit board Quote Link to comment Share on other sites More sharing options...
Tomas. Posted April 26, 2018 Author Share Posted April 26, 2018 Don't believe the vents are plugged. Was working fine last night Quote Link to comment Share on other sites More sharing options...
AKIQPilot Posted April 26, 2018 Share Posted April 26, 2018 1 minute ago, BOHICA said: plugged vent? There isnt (or doesnt appear to be) a flow switch in the system so i doubt it would notice a plugged vent. The furnace ran fine all winter and then just stopped today. Quote Link to comment Share on other sites More sharing options...
AKIQPilot Posted April 26, 2018 Share Posted April 26, 2018 So does the furnace fire momentarily and then immediately shut off? The init has a standing pilot I assume? Can you see or access the pilot? What position is the red switch in on the gas valve? Quote Link to comment Share on other sites More sharing options...
Tomas. Posted April 26, 2018 Author Share Posted April 26, 2018 I can see the pilot and it is lit. The induction motor will run for some time trying to lite but the main burners never fire up. The pilot is the only thing going on in the chamber Quote Link to comment Share on other sites More sharing options...
AKIQPilot Posted April 26, 2018 Share Posted April 26, 2018 When you hear the gas valve click does it make just one solid click or does it click once and quickly click again? Quote Link to comment Share on other sites More sharing options...
Tomas. Posted April 26, 2018 Author Share Posted April 26, 2018 One solid click Quote Link to comment Share on other sites More sharing options...
AKIQPilot Posted April 26, 2018 Share Posted April 26, 2018 Set your meter to volta AC. With the furnace not running check the gray wire coming out of the gas valve. It should show no voltage. Next let the furnace go through its cycle. Once the gas valve clicks there should be about 24 volts on the gray wire coming out of the gas valve. Quote Link to comment Share on other sites More sharing options...
Tomas. Posted April 26, 2018 Author Share Posted April 26, 2018 (edited) If I have this on the right setting, and the leads in the right spots (black to ground and red to grey wire, it reads 0 both on and off 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 The blue wire between the pressure switch and the gas valve should also have about 24 volts when the gas valve clicks. Quote Link to comment Share on other sites More sharing options...
AKIQPilot Posted April 26, 2018 Share Posted April 26, 2018 So check the blue wire now. When the gas valve clicks you should see 24v there. Quote Link to comment Share on other sites More sharing options...
Tomas. Posted April 26, 2018 Author Share Posted April 26, 2018 (edited) Yes it does, blue has 24 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 Ok so things are pointing at a bad gas valve. Ben called it a few pages back. Hahaha. Im no expert but it seems everything is working like it should except the gas valve. For a more expert opinion you might try googling your model furnace and bad gas valve and see what you can find there. Quote Link to comment Share on other sites More sharing options...
Tomas. Posted April 26, 2018 Author Share Posted April 26, 2018 9 minutes ago, AKIQPilot said: Ok so things are pointing at a bad gas valve. Ben called it a few pages back. Hahaha. Im no expert but it seems everything is working like it should except the gas valve. For a more expert opinion you might try googling your model furnace and bad gas valve and see what you can find there. This all that I can find on the internet but it looks like all roads lead to gas valve Quote Link to comment Share on other sites More sharing options...
motonoggin Posted April 26, 2018 Share Posted April 26, 2018 Whack the valve a few times with a wrench before you tear it out. It might just be sticky. Quote Link to comment Share on other sites More sharing options...
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