Why when I turn my oil heating on does it knock my electric off

Can you provide more details? What kind of heater do you have? How much is turning off?

I can only guess at the problem you have but I'll give it a swag anyway.

Did you mean to say that when the heat (oil fired furnace) comes on, the circuit breaker for the furnace trips off? Or did you mean that the entire panel trips off when the furnace comes on?

Nothing has changed on the furnace, no work was recently completed to prepare for this winter season?

If that is true that I suspect that the blower motor circuit is failing because of high startup inrush current used by the motor. Could be a motor failure, a flaky circuit breaker. You could even have a short in the wiring to the motor.

Based on the depth of your comment, I would recommend hiring a professional...

Why when I turn my oil heating on does it knock my electric offPlease try again. This question makes no sense.