The batteries are likely dead. Install only non-alkaline batteries. However, if your heater runs on non-alkaline batteries but yet it's not glowing, then you might have to replace the igniter. Make sure to place the igniter properly above the wick to prevent igniter burn-out.  Overall, kerosene heaters can pose a serious threat if you aren't familiar with their proper operation. However, you can avoid most hazards and risks by following the instructions stated by the heater's manufacturer.