First read the Manual that applies to your stove, then read FirePotPete's cleaning thread.
https://www.hearth.com/talk/threads/ussc-6039-6041-internal-cleaning.152067/
Then either start fire or run the factory test.
6039 4 Digit Control Board Test
To run this test the UNIT MUST BE COOLED OFF. Power up the unit by plugging in the
power supply cord to the back of the unit. Press the on button and the circuit board then
press and hold the Off and Auger Delay buttons simultaneously for 3 seconds. To advance
through the test press the on key. If the Heat Range lLight is on during every test check
Hopper Switch Wires.
1. Exhaust Fan Output Test- The display will show “OUT1”. The exhaust fan is turned on
full then reduced to a level just above the typical minimum pressure switch setting. The
ON LED indicates whether the pressure sensor is detected. Press the ON button to move
to the next step.
2. Room Fan Output Test – The display will show “OUT2”. The room fan is turned on full.
Press the ON button to move to the next step.
3. Agitator Output Test – The display will show “OUT3”. The Agitator motor is turned on
full. Press the ON button to move to the next step.
4. Auger Output Test – The display will show “OUT4”. The auger motor is turned on full.
The ON LED will be lit when the over temperature is in cool state. Press the ON button
to move to the next step.
5. Low Limit Switch Test – The display will show “IN 1”. If the stove is warm (above
110°F), the ON LED will turn OFF. If the stove is cool the ON LED will be on. Press the
ON button to move to the next step.
6. Thermostat Test – The display will show “IN 2”. If the thermostat input is closed, the ON
LED light will be on, otherwise it will be off. Press the ON button to move to the next
step.
7. Temperature Test – If equipped with an RTD sensor it measured the temperature and
will display in 0° F. Press the ON button to move to the next step.
8. AC Frequency Test - Displays the measured AC frequency in hertz followed by the letter
“H”.
This should read 59, 60, or 61H. Press the ON button to move to the next step.
or ABC test depending on which control board you have
6039 ABC Board Test
To run this test the UNIT MUST BE COOLED OFF. Power up the unit by plugging in the power
supply cord to the back of the unit. Press the on button
Step 1: Press and Hold down the A and B buttons at the bottom of the board until the display shows
an “0” and a “1”. This steps checks the Exhaust Blower and Vacuum Switch. Check to see if the
Blower is running and if the Red LED is on above the A button. Open the door and see if the LED
goes off; shut the door and make sure it comes back on. If the A is not on in this step check the
gaskets on the door and clean the units exhaust blower and ash cleanouts Vacuum Issue. If so, Press
the ON button to go to the next step.
Step 2: Display will show an “0” and “2”. This step checks the Room Blower. Check to see if the
room fan is running. If so, Press the ON button.
Step 3: Display will show an “0” and “3”. This step checks the Agitator. They should see it turning
clockwise in the burnpot. If so, Press the ON button
Step 4: Display will show an “0” and “4”. This step checks the Auger Motor. With the hopper lid
closed, the auger motor should be running. If so, lift the lid to check the micro switch mounted on
the right side of the hopper; the motor should stop. Close the lid to make sure that the motor comes
back on. If so Press the ON button.
Step 5: Display will show an “I” and “1”. This step checks the low temperature switch. It will
turn on the LED over the “A” if the low temperature switch is open which means it is at room temp.
If so have them Press the ON button. The “A” light will be off if the switch is closed and this tells you
it is hot.
Step 6: Display will show an “I” and “2”. This step checks the Thermostat Plug. Make sure that
the LED (Red light) over the A button is on. If so, Press the ON button to go to the next step.
Step 7: Display will show a numerical value. This is the room temperature measured at the
thermistor attached to the exhaust housing. The displayed temperature should be close to the
room (ambient) temperature. NO temp reading (00) thermistor disconnected from the board
or bad board. Press the On button to go to the next step.
Step 8: Display will show the Frequency of the A/C input voltage. Display should show a 59, 60,
or 61. If so, Press the ON button to go to the next step.