Hi. My rheem heating unit stopped working. It doesn't turn on. Nothing

Replaced igniter. Still nothing

Any lights on the control board? If no, Start by checking to see if there is even 120v to the furnace. Check breakers, and ssu fuse if present.

Checked fuse and breakers. Went back up and 2 green lights on and one orange not on. All so forgot to put door cover on after igniter replaced.

Okay, so when you put the door back on does the furnace work? The orange light will only come one when the burners are lit. Its just to show that the flame is being sensed.

Now, if the two green lights are on steady, this is normal. If the furnace isn't doing anything, check to make sure you have a call for heat from the thermostat. To do this, check for 24v between r and c on the control board, then check for 24v between w and c on the board. Let me know what you find and we will take the next step.