schurchill39
12-21-2018, 07:31 PM
I've had a pile of issues with my 5 year old Lennox furnace as of late. November 18th I replaced the original limit switch because I figured it was prematurely tripping. It would trip, kick the furnace out, but then as soon as it reset everything would fire back up. It would just cycle constantly. After replacing it everything worked fine up until today.
Today's issue is that the furnace stopped working again due to the limit switch tripping, but this time after it resets the burner will fail to ignite 4 times until I get an error and everything just shuts down. The sequence looks like this:
1. Furnace fires up, everything is fine.
2. Limit switch trips, kicks furnace out, fan stays running to cool it down.
3. After approx 1m30s the limit switch closes, and the ignitor starts glowing again. The gas valve clicks open, and it ignites but with a really weak flame.
4. Flame peters out after about 10 - 15 seconds. Gas valve closes.
5. Goes the the sequence of ignitor glowing, gas valve clicking open, but no flame. Gas valve closes
6. Repeat #5 3 more times then I get the "burner failed to ignite 4 times" error.
If I shut the furnace off, leave it for 5 minutes, it goes through this whole 1-6 again. If I jump the limit switch so it never trips in the first place then my furnace fuctions as normal.
My question is, last time the limit switch went, as soon as it would close everything would fire up again until it tripped. This time after it closes it wont. Should I be replacing the switch again, or is there anything else I should be looking at? Want to try and go out and get parts ASAP with Christmas coming, or if it continues to stump both my google skills and beyond finally call in a professional and remortgage my house to pay for the call out fee.
Today's issue is that the furnace stopped working again due to the limit switch tripping, but this time after it resets the burner will fail to ignite 4 times until I get an error and everything just shuts down. The sequence looks like this:
1. Furnace fires up, everything is fine.
2. Limit switch trips, kicks furnace out, fan stays running to cool it down.
3. After approx 1m30s the limit switch closes, and the ignitor starts glowing again. The gas valve clicks open, and it ignites but with a really weak flame.
4. Flame peters out after about 10 - 15 seconds. Gas valve closes.
5. Goes the the sequence of ignitor glowing, gas valve clicking open, but no flame. Gas valve closes
6. Repeat #5 3 more times then I get the "burner failed to ignite 4 times" error.
If I shut the furnace off, leave it for 5 minutes, it goes through this whole 1-6 again. If I jump the limit switch so it never trips in the first place then my furnace fuctions as normal.
My question is, last time the limit switch went, as soon as it would close everything would fire up again until it tripped. This time after it closes it wont. Should I be replacing the switch again, or is there anything else I should be looking at? Want to try and go out and get parts ASAP with Christmas coming, or if it continues to stump both my google skills and beyond finally call in a professional and remortgage my house to pay for the call out fee.