What’s wrong with my furnace?

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Q: We recently moved into a home with electric forced-air heat. In the winter, every time the furnace kicks on, the lights in the house dim for a nanosecond. Is this something that can be addressed or fixed? Before we moved in we had to replace the electrical panel (it was made by a company that went out of business years ago because their panels were known to start fires), and I'm wondering if there is something associated with that we can correct. Any help before furnace season starts is greatly appreciated! --Lea A: The dimming of the lights is caused by a voltage drop that occurs during the startup phase of the furnace. When your thermostat calls for heat, the electric elements in the furnace begin to heat up before the furnace motor kicks on, a process called "heat anticipation." It's set up that way so that the furnace fan doesn't blow cold air through the ducts before the furnace itself heats up. So when you hear the furnace kick on, that's actually the sou...