Flickering Lights (oscilloscope capture included)
#1
Member
Thread Starter
Flickering Lights (oscilloscope capture included)
Hey All,
Ever since putting in my EcoSmart ECO 27kW tankless water heater I've had LED lights flicker when the hot water is running. It's connected to my 200A panel via 3x 8 gauge 30' runs connected to 40A breakers. The issue isn't just one specific type of LED bulb, I've got a variety of LED bulbs/fixtures and they all flicker to some extent. I borrowed an oscilloscope and safely took a capture of what the line voltage of one of the phases looked like while it was flickering, this was a random circuit on the other side of the house from the water heater, see below. I didn't install the water heater but after reading suggestions online I went ahead and attempted to tighten the terminals on both sides, after turning off the main breaker, but they were already extremely tight, and it didn't fix the flickering issue.
Is this something worth showing my electric company? Or is there anything I can do about it, like install a capacitor near the water heater to smooth out the voltage? Any advice would be greatly appreciated!
Ever since putting in my EcoSmart ECO 27kW tankless water heater I've had LED lights flicker when the hot water is running. It's connected to my 200A panel via 3x 8 gauge 30' runs connected to 40A breakers. The issue isn't just one specific type of LED bulb, I've got a variety of LED bulbs/fixtures and they all flicker to some extent. I borrowed an oscilloscope and safely took a capture of what the line voltage of one of the phases looked like while it was flickering, this was a random circuit on the other side of the house from the water heater, see below. I didn't install the water heater but after reading suggestions online I went ahead and attempted to tighten the terminals on both sides, after turning off the main breaker, but they were already extremely tight, and it didn't fix the flickering issue.
Is this something worth showing my electric company? Or is there anything I can do about it, like install a capacitor near the water heater to smooth out the voltage? Any advice would be greatly appreciated!

#2
We've had other members with the same complaint.
That heater uses 3) 9kw sections that turn on and off based on demand.
You may have an undersized service causing that problem. Your service and panel is 200A but you don't know what the poco is supplying. Typically if you have an aerial service..... the drop is 00A.
Did you notify the poco you were connecting that device in your house ?
Doubtful they'll increase the service size to your house but do check into it anyway.
That heater uses 3) 9kw sections that turn on and off based on demand.
You may have an undersized service causing that problem. Your service and panel is 200A but you don't know what the poco is supplying. Typically if you have an aerial service..... the drop is 00A.
Did you notify the poco you were connecting that device in your house ?
Doubtful they'll increase the service size to your house but do check into it anyway.
#3
Member
Thread Starter
It's underground service, neighborhood built in 1988. No I don't think they were ever notified of a tankless water heater in the home. I just got the lights to flicker hard by turning on a few faucets on hot, and I'm reading around 80A total coming into the house, using a clamp meter, and nearly all of that is the water heater, nothing else big is on.