Lights flickering when the AC turns on
Compressor assist devices often fail to stop lights from dimming when an air conditioner starts up, leaving homeowners worried about safety and old wiring. This sudden power draw causes lights to flicker for a few seconds every time the HVAC unit kicks on, even after expensive repairs.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
Found another way around this?
Share your steps and trade-offs so fellow engineers don't have to reinvent the wheel. No account required.
- 1installing better dimmers and light bulbsDid this help you?
- 2living with the dimming as a characteristic of older home wiringDid this help you?
- 3Turning off animal lights, fans, and computers to see if it stops the dimmingDid this help you?
- 4Considering plugging the AC or other devices into a different outlet or using an extension cordDid this help you?
- 5Checking the refrigerant level and performing a recharge.Did this help you?
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“I've noticed that the AC unit draws more and more power as the year has gone by. My main light and fan that's constantly going will dim for for a second or two and then pick up pace again”source ↗
“when I turn my AC unit off the flickering and dimming stops.”source ↗
“Is my room at risk of catching fire? Any advice would be helpful! I genuinely don't want to break anything or risk mine, my family, or my animals lives!”source ↗
“Installed a compressor assist device to stop my lights from flickering every time my AC kicks on but they’re still flickering”source ↗
“Guy says I likely have old wiring but I paid like $400 for the part and service, and he said it would fix the flickering.”source ↗
“The noise only happens when the AC is on. In the video, you’ll hear it right away, then it goes away when the AC is off, then comes back when turned on again.”source ↗