I have an oil heating system that was working fine on auto mode like it should. Then a few days ago after the heat had been on and off all day pretty much I went to turn the temp up so it would kick in and the thermostat clicked like usual, but the unit didn't turn on to give me any heat.

This isn't a problem with my AC, it works fine on auto, and the fan comes on if I put it on on instead of auto. I just moved in here and the last tenant filled up the oil tank so I'm pretty sure its not empty, I haven't double checked though... Ive tried pressing the reset button on the unit but still the thermostat just clicks like usual but the heating doesn't come on... what could be the issue?

Thanks!

Make sure 120 volt power is available to the oil burner.

Try pressing the reset one more time.

Make sure that 24 volts is being applied from the thermostat signal source to the start control usually mounted to the burner. This is the same control that has the reset button on it.