Thermostat/fan troubleshooting
#1
12-02-18, 09:43 PM
Thermostat/fan troubleshooting
I have Honeywell T8000C thermostat. Not sure if I have fan problem or thermostat problem.
When I set thermostat to heat/auto-fan mode, I can hear the furnace turning on, thermostat shows the flame symbol, but no hot air is coming from the registers (even after waiting for 10 minutes).
When I set the the AC/auto-fan mode, I see the snowflake symbol, but no cold air coming from the registers. Outside unit does not turn on.
When I set Cool/Heat switch to OFF, and fan switch to ON, fan does not start (no air from registers).
The circulating fan does not turn on in either case. Do I have fan problem or is thermostat fan control/switch is bad?
How do I troubleshoot where/what the problem is?
When I set thermostat to heat/auto-fan mode, I can hear the furnace turning on, thermostat shows the flame symbol, but no hot air is coming from the registers (even after waiting for 10 minutes).
When I set the the AC/auto-fan mode, I see the snowflake symbol, but no cold air coming from the registers. Outside unit does not turn on.
When I set Cool/Heat switch to OFF, and fan switch to ON, fan does not start (no air from registers).
The circulating fan does not turn on in either case. Do I have fan problem or is thermostat fan control/switch is bad?
How do I troubleshoot where/what the problem is?
#2
12-02-18, 10:47 PM
Group Moderator
It's hard to say what the problem is because you not only don't have the blower coming on...... you don't have the outside unit coming on in A/C either. That indicates a problem a little more serious than just the blower.
Did you wait for 5 minutes when going to A/C mode ? The condenser has a 5 minute turn on delay.
If you check it again.... wait at least the 5 minutes for it to start. If it does.... you have just a blower problem.
If your blower is out..... that will take a meter to do some checking for power to the motor.
Did you wait for 5 minutes when going to A/C mode ? The condenser has a 5 minute turn on delay.
If you check it again.... wait at least the 5 minutes for it to start. If it does.... you have just a blower problem.
If your blower is out..... that will take a meter to do some checking for power to the motor.
#3
12-08-18, 10:06 AM
Thanks Pjmax. Here is what I did to troubleshoot....
I shorted G and R wires => fan did not start
I shorted W and R wires => furnace started
I shorted Y and G wires => outside compressor unit started.
I think the fan is busted. Any tips on troubleshooting the fan? Do I need to replace the fan or can it be repaired?
I shorted G and R wires => fan did not start
I shorted W and R wires => furnace started
I shorted Y and G wires => outside compressor unit started.
I think the fan is busted. Any tips on troubleshooting the fan? Do I need to replace the fan or can it be repaired?
#4
12-08-18, 10:32 AM
Group Moderator
It could be just a capacitor on the blower motor or the motor is bad or there is a problem with the control board. There's no guessing. You will need a meter to do testing.
