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Furnace Cycling at least twice before catching

Posted by RaymondTJackson (My Page) on
Sun, Nov 10, 13 at 0:09

My furnace cycles on and off, sometimes several times before it actually catches and sometimes it will actually fault and the led will blink, signalling a lock out. I have had a furnace guy over and we replaced the flame-sensor, the computer and he blew the pressure tub to make sure it was clear. I have some video of the problem here:

And here:

If these links don't work please let me know.

In dealing with this problem, I made a few changes in the furnace which may or may not have affected the issue of multi-cycling. When looking at the furnace closer I noticed that the burner in front of the flame sensor was upside-down. Even though it didn�t lot like it was of any material significance, I took it out and flipped it right-side up. While I was at it, also switched it with the burner two burners down from it. That seems like it might have helped it a little, and it might have been wishful thinking, because for the first week or so, the furnace seem to start on the first cycle. But now it takes at least two cycles, but it is better than it was. If you have time check out these videos to see what's going on. They might give a clue to what is going on. Thanks again.

Follow-Up Postings:

RE: Furnace Cycling at least twice before catching

Check the flame roll out and pressure switches. Also check to see if the heat exchanger is cracked.

RE: Furnace Cycling at least twice before catching


Roll outs have been checked as have the pressure switch (there is only one on my furnace that I know of). How do you check for a cracked heat exchanger? I have heard that suggestion before, even before I made the videos. Thanks.

RE: Furnace Cycling at least twice before catching

Do a Google search. You will find several explanations and Youtube videos.

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