Not sure if this is associated with the grid heater or not. But I have noticed sometimes the ac fan at start up will be at a slower speed, and when I hit the gas it will speed back up to normal speed when on high. Is this associated with the amp draw of the grid heater?

 

yeah sounds like grid heaters for sure, they draw alot. You will probably notice your lights dim, blower motor slow down, and volt meter drops a fair bit. Perfectly normal and nothing to worry about.