Beachcomber72
Well-Known Member
Is the replacement thermostat the same as your old one?
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Error code legend should be on inside/outside blower door cover or on blower housing.Well new thermostat did not fix it. It’s showing error code 34 now and I can’t get ignition. I was getting ignition before the new thermostat
Edit 1: just got ignition
Edit 2: now showing error code 12 again
Look for the “diagnostic light code legend” on the door covers and see what the flashing light code isHere is a full video of what’s happening
several years ago, I had a similar issue. After replacing the board and valve, I discovered the drain line was frozen where it exits the house ( there was a slight dip in the drain line allowing it to hold water.) After thawing the drain line, it worked perfectly. I then rerouted my drain line to allow a better flow downhill. Problem solved. Long story short, check your drain line.Please help me. This has had me scratching my head for a week. Iv had a tech come out and they’re scratching their head and trying to throw parts at it.
It’s a carrier furnace model number :58MXB080-F-10116
So far, I have replace flame sensor, gas valve, capacitor, filter - no difference in any of the repairs.. arguably, got a little worse after the new gas valve as it would sometimes work for a day or so with the old gas valve, now we get consistent failures.
Here are the symptoms:
When unplugging or off for a long time, and turned on, the fan relay will click on and off several times and eventually the fan will start after about 10-15 clicks with the fan turning on for longer periods of time each time but usually not for more than a fraction of a second to 1 second.
If I go to the thermostat and turn to heat and fan on, I can eventually get the inducer motor to turn on first, then the coils will ignite, then the coils turn off, and the fan comes on.
After the fan is on for about 30 seconds, the fan relay clicks and the fan turns on and off for a second multiple times and will actually turn the fan on for 30 seconds then go back to on and off for a second. The cycle will continue until I turn off the thermostat.
If I turn on the thermostat again, the inducer motor will start, coils will ignite, and the cycle continues as above.
Seems as if the fan works, the inducer works, the gas valve works, the coils are working, but something isn’t working correctly to make it all work together except for the beginning of the cycle when I turn the thermostat on for the first time.
Here are some videos:
Initial startup after being unplugged or off for a long time:
Here is what happens when I turn on the thermostat:
Then, the coils turn off, the inducer motor turns off, and the fan turns on
Then the fan turns off, and you can hear the relay clicking to turn the fan on again
After a few attempts, the fan will turn on for about 30 seconds, then the cycle continues of attempting to turn the fan on again
Here is a full cycle:
Any help is appreciated. If someone can diagnose the correct fix, I’ll send them some $$$$!
what does the drain line look like so I can check?several years ago, I had a similar issue. After replacing the board and valve, I discovered the drain line was frozen where it exits the house ( there was a slight dip in the drain line allowing it to hold water.) After thawing the drain line, it worked perfectly. I then rerouted my drain line to allow a better flow downhill. Problem solved. Long story short, check your drain line.
a physical obstruction somewhere like the drain, exhaust, or ductwork.
Based on that video I’d lean now more towards blockage vs faulty pcb. What code is the system currently showing?Here is a full video of what’s happening
new board will be here Wednesday, I pray you’re rightLooking at your video, the time delay between when the burners ignite and the circulating air blower comes on is longer than it should be. A high limit is then turning off the burners and it goes into a cool down mode. That on and off is the timing circuit malfunctioning. A bad circuit board is the most likely cause.