My elderly mother has an electric coal effect fireplace. She has oil central heating but likes to put the fireplace on in the evenings for the effect. Trouble is it keeps blowing bulbs. It has two bulbs under the plastic coal fitting and I'm using the recommended 40 watt bulbs but they only last on average 2 months. I replaced both of them at the end of July. One lasted a month and the other went last week. I'm concerned now that there may be an electrical problem with the fireplace. Should I replace it for the sake of safety or is there some reason why the bulbs could be blowing?