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My fluorescent light will not come on when the temperature in room is above 70 °F. When it is below 70 °F it works fine and comes on every time. When it is above 70 °F, it will not come on at first, but it will come on if I rotate one of the bulbs in its socket a little. What is wrong?

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Thermal Expansion. – Tester101 Nov 26 '12 at 17:43

Is this a cfl or tube fluorescent bulb? And to be honest i have never heard of this. I do know some older t12 bulbs with magnetic ballasts fail to operate at low temperatures roughly 32 degrees F. They should work better at warmer temperatures. I know with newer t12 bulbs that have electronic ballasts operate at lower temperatures than magnetic ballasts as well as t8 and t5 bulbs due to their electronic ballast. Cfls operate roughly the same was as electronic ballasts. You shouldnt have to turn ur bulb to have it light up. It could possibly be a bad bulb. Have you tried a different bulb in the same fixture to see if it is just the bulb?

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