Hello everyone, It's getting colder in my house every minute
I have Carrier 58TUA furnace
It work great until yesterday when I've noticed that it never turns
off for some reason
I got new thermostat first but quick fix failed
I can only turn it off using switch on the furnace

LED error code is 12

BLOWER ON AFTER POWER UP (115 VAC or 24 VAC) -Blower runs for the
selected blower off-delay time, if unit is powered up during a call
for heat (R-W/W1 closed) or (R-W/W1) opens during blower on-delay

Is that control board went bad?

Thanks ahead

ypylaw1 wrote:
Hello everyone, It's getting colder in my house every minute
I have Carrier 58TUA furnace
It work great until yesterday when I've noticed that it never turns
off for some reason
I got new thermostat first but quick fix failed
I can only turn it off using switch on the furnace

LED error code is 12

BLOWER ON AFTER POWER UP (115 VAC or 24 VAC) -Blower runs for the
selected blower off-delay time, if unit is powered up during a call
for heat (R-W/W1 closed) or (R-W/W1) opens during blower on-delay

Is that control board went bad?

Thanks ahead

It is the cycle that the heater goes through when the power is returned AND
the wall thermostat is calling for heat. [90 sec. blower run time.]

If the blower won't quit running after you plugged in the heater, and you
are sure the wall thermostat [fan] switch setting is to AUTO, then it is
likely you have a situation that requires a qualified CARRIER service tech
see why it's doing what it's doing. I know what the problem is, and it
[honestly] should be checked out. You [might] have either a firebox
failure, flame roll out condition, or a conditioned air mixing with
combustion air problem. All of these are dangerous and should not be
addressed by a DIY. Call a licensed HVAC company and have them check your
unit.


--
Zyp

Maybe I stated the problem wrong
I have thermostat turned off yet furnace starts to run heats the
house
It just never stops
LED does go red after 90 sec
another thing that troubles me is that if board is bad
can I trust the error code that I'm reading from the board?

I got it fixed
the thermostat cable got shorted in the wall
I end up running new one
took me all day to get the cable in place
thanks

Bubba, he's playing your song. Replace the thermostat (cable).


There's a little difference between replacing thermostat and replacing
cable that leads to is. Is it not
Stormin Mormon?