<p>As part of my bathroom remodeling, I had the light fixture over the vanity replaced yesterday. There used to be eight light bulbs over each vanity; now there’s only four. All together, I had four sets of light fixtures replaced. So far, out of the 16 light bulbs that are now in use, 2 have literally exploded, even when the switch is OFF!! The bottom of the light bulb is still screwed to the base of the light fixture, but the bulb part has blown off. Something is definitely wrong, but I’m not sure if it’s a wiring problem or a simple light bulb problem. I will ask the electrician when he comes today but I’m just curious if this has ever happened to any of you. </p>
<p>How can a light bulb explode even when the switch has been OFF for hours??? Does this mean it’s more of a wiring problem rather than a light bulb problem? I thank you in advance for any comments or insights you may have on this weird phenomenon.</p>
<p>For vertically mounted lights there are differences between those mounted facing down and those facing up. Perhaps you purchased the wrong lights.</p>
<p>Two ideas: 1) your bulbs might be the wrong wattage for the fixture; 2) your bulbs might be “bad” (try a different brand, preferably long life).</p>
<p>There is also a possibility that the fixture has faulty wiring, but I’d try the other ideas first.</p>
<p>Thank you for taking your time to answer my question! I have replaced all the bulbs with brand new, lower-wattage bulbs, and so far so good; none of them has exploded yet!</p>
<p>Might you have a problem with dampness, either a leak or condensation causing water to collect that shorts out either the bulb or the switch, causing current to flow even though the switch is in the off position? Since the fixture is in a bathroom, you should have a GFCI outlet somewhere in the same room. If the GFCI is tripping unexpectedly, get the electrician on the case ASAP.</p>
<p>Another possibility is that the fixture is a little out of kilter making you screw in the bulb a little tighter than you should to make electrical contact. When you do that, it can cause a scratch in the glass of the bulb. The scratch expands after several on/off cycles due to thermal stress and eventually the weight of the bulb is enough to cause it to snap somewhere near the base.</p>
<p>EDIT: did not see your latest post until after I posted mine (the dog and my wife both interrupted me in the middle of my post). If you were using cheap bulbs that draw more current than the fixture is rated for, that would indeed cause bulbs to pop.</p>