Anyone know anything about gas furnaces?

[metalchips]

The round things are flame roll out switchs/ high temp switchs if they get two hot it shuts the gas off to the gas vavle. Now it almost looks like when it first trys to start the gas valve is not putting enough gas out to light all three burners. Have you tried to hit the gas valve when the first one is burning. If it was a flame sensor then all three burners would come on and then go off a little while later.

Cool

[mnc2fan]

I tried tapping the valve, and that didn't do anything. Then got the multimeter out.. and well my fuse is bad in it. I'll get one tomorrow and check. If that checks out, does that pretty much the valve could be bad?

[hunt4game29]

Yeah check to see if you have 24 volts when its messing up. If it does i would say its the valve but i hate to tell you it is with out seeing it in person and then it not be. But when i have seen others heaters act kinda like this its been the gas valve. But its hard to say with all the other things some heater have and some dont as far as saftys and what not.

So check the 24 volts before its on when it starts ect. It should have it a little bit after the ignitor starts to glow. See if you lose it when the gas stops or what. Thanks matt

[MikeGyver]

Sorry I didn't check in yesterday, as soon as I saw your video I knew what your problem is. The burners are dirty. You need to take them out and blow them out with compressed air, problem fixed.
At the flame end of the burners, where they are screwed down and connected together, with the wing-shaped stamping, is a channel for the flame to travel from burner to burner. There is either a cobweb in there, or dryer lint. After you fix the furnace, check to see if your clothes dryer exhaust is clogged.
This is my job, your problem is very common.
Oh, yeah: if there is a flame rod, it is always a good idea to give it a swipe with sandpaper. Scotchbrite is only OK if you are sure the rod is cold, it can melt and ruin the flame rod. If you don't have a flame rod, the ignitor can be the sensor in some systems. I think you do have a flame rod, because if the ignitor was the sensor, it should stay running with that right hand burner firing, and I think I see it behind the left burner.
If the ignitor is the sensor, then you have dirty burners and a bad ignition module.

[mnc2fan]

Yeah check to see if you have 24 volts when its messing up. If it does i would say its the valve but i hate to tell you it is with out seeing it in person and then it not be. But when i have seen others heaters act kinda like this its been the gas valve. But its hard to say with all the other things some heater have and some dont as far as saftys and what not.

So check the 24 volts before its on when it starts ect. It should have it a little bit after the ignitor starts to glow. See if you lose it when the gas stops or what. Thanks matt

Still have to get a fuse for my tester. So haven't tested that yet. But will.

Sorry I didn't check in yesterday, as soon as I saw your video I knew what your problem is. The burners are dirty. You need to take them out and blow them out with compressed air, problem fixed.
At the flame end of the burners, where they are screwed down and connected together, with the wing-shaped stamping, is a channel for the flame to travel from burner to burner. There is either a cobweb in there, or dryer lint. After you fix the furnace, check to see if your clothes dryer exhaust is clogged.
This is my job, your problem is very common.
Oh, yeah: if there is a flame rod, it is always a good idea to give it a swipe with sandpaper. Scotchbrite is only OK if you are sure the rod is cold, it can melt and ruin the flame rod. If you don't have a flame rod, the ignitor can be the sensor in some systems. I think you do have a flame rod, because if the ignitor was the sensor, it should stay running with that right hand burner firing, and I think I see it behind the left burner.
If the ignitor is the sensor, then you have dirty burners and a bad ignition module.

As far as the dust or something in the burners, I caught it when the furnace was coming on. Of course it didn't come on, so I blew through the burners, and tapped on them pretty hard, when it tried to light again it did, but I can't tell if it was from dust or if it was just working right the second time. And I saw the sensor on the left burner tube, pulled it out.. and well its been sanded before, and it has a pretty big brownish spot on it.




Sanded it off. See how that goes, and when I get home I'll pull those burner tubes out and makesure those are clean. And I'll test the valve for 24v too.

[MikeGyver]

...As far as the dust or something in the burners, I caught it when the furnace was coming on...and tapped on them pretty hard...

If I could fix furnaces over the internet I would get stuck to the couch. (Home sick today) I as going by what I saw in the video, my diagnosis is still the first thing that I would check, but your banging on stuff and getting intermittant lighting makes me think gas valve, as hunt4 said. If when the right burner lights, and you are holding a lit propane torch pointing at where the flame should be in the middle burner, and it lights, I would still suspect dirty burners.
Your flame rod is fine.

[mnc2fan]

It does get 24v to the valve, when it tries to light, something cuts the 24v and the gas cuts off. I do appreciate the help. Its given me lots of things to try.

Something else. What happens if the intake for the furnace is too small? I think I just answered that, the furnace intake is 16x25, the actual hole for the intake is 8x25. Any thoughts on that? Its a 60k btu unit.

[MikeGyver]

How can you go this long without a furnace?
After watching your video again, I am going back to my dirt answer.
What you will notice with not enough return (intake) air is the flames will light normally and run for awhile. In anywhere from a couple to several minutes, the flames will shut off even though the thermostat isn't satisfied. The blower will remain running like it normally does after the flames shut off, except after a few minutes the ignition cycle will start again. It is normal for the blower to stop at the start of each ignition cycle, so that is not an indicator. The only way you can be sure that the thermostat has not reached setpoint when the flames go out is to test across the "R" and the "W" low voltage terminals. If your meter shows no voltage, the thermostat is still calling. If you have voltage from terminal to terminal, the thermostat is satisfied.
There is a limit switch that senses the air temperature downstream of the burners. When the switch gets too hot because of a lack of airflow, it kills the burners and keeps the blower running until it cools off and the cycle starts again.
If this is happening to your furnace, it is a seperate issue from what is happening in your video.

[mnc2fan]

How can you go this long without a furnace?
After watching your video again, I am going back to my dirt answer.
What you will notice with not enough return (intake) air is the flames will light normally and run for awhile. In anywhere from a couple to several minutes, the flames will shut off even though the thermostat isn't satisfied. The blower will remain running like it normally does after the flames shut off, except after a few minutes the ignition cycle will start again. It is normal for the blower to stop at the start of each ignition cycle, so that is not an indicator. The only way you can be sure that the thermostat has not reached setpoint when the flames go out is to test across the "R" and the "W" low voltage terminals. If your meter shows no voltage, the thermostat is still calling. If you have voltage from terminal to terminal, the thermostat is satisfied.
There is a limit switch that senses the air temperature downstream of the burners. When the switch gets too hot because of a lack of airflow, it kills the burners and keeps the blower running until it cools off and the cycle starts again.
If this is happening to your furnace, it is a seperate issue from what is happening in your video.

It works, just takes it a few tries to get it to come on. No its not doing anything like that, only issue I know of is whats in the video. I'm agreeing on dust or dirt, I'll attack that in the morning, pulling out the burner and cleaning them.

[hunt4game29]

Hope cleaning works. Let us know if it does not.

Also what state do you live in. I am guessing up north some where from the snow pics.