Light keeps going off and on? Need some help here!

The bulb might be 3 or 4 years old? Are you serious? Are you aware they're really only good for 6 months to a year max? They completely drop off in efficiency and light output in the 6months to a year range and if they're still working beyond that you can end up with HALF THE LUMENS and drawing MORE POWER. (I'm talking age as in time in use, not time on a shelf if that's what you meant by how old it is.)

You should never never never never never never NEVER run a bulb this long, you are costing yourself so much lumens and growth that the 400w light with a new bulb might equal the 1000 with an old one like that. Also it is VERY BAD for the ballasts, makes them run out of specs, luckily yours is thermally protected or it might have just kept on working until the ballast died.

Well 6 months to a year no stop......He might not have been using it for 4 years strait.

The fact that his house lights do flicker when the heat kicks in is a pretty good sign that it is an older electrical system (1978 like he said) So chances are its not the ballast. I think the most important thing to do is replace that bulb ASAP. A good way of determining how much life is left in the bulb is to look at the bulb when its off and fully cooled, the inner core will get black on the ends over time.


And are you sure your ballast has a thermal breaker? Just assuming this is a bad idea.

I would get a new bulb, fire it up, and spend the day keeping an eye on my whole electrical system, every few hours feel the side of your breaker pannel, make sure there aren't any warm spots, also where the ballast plugs in, make sure its not abnormally warm. If the problem continues or you notice some warm spots then its probably your electrical system. If the problem stops, and everything else is running OK then you should be good to grow.

ok new evedance points souly to the bulb. nothing at all to do with circuites in the house enless they installed some 1.5 for the electrics. 2.5 can handle around 15-20 amps 4-6 amps for ballast and only other thing thats big is heater starting up amps would be around 8 amps and if i read right is on a differnt circuite. so that leaves us with 3 amps at least if the heater was on the same circuite. enless ur coming off the light circuite or when the shed was put in the just linked it to a already existing circuite. replace the bulb if still happens send the ballast to a specialist tell them whats happening and how much would cost. i agree with oregon old equipment was built to last but they are a lil bit more power consuming.

Magnetic ballasts really havent changed much. They will last a long time if properly maintained, but thats means replacing all the wiring in the ballast every few years just to be safe. I usually just replace the ballast cause the magnetics are so damn cheap.

Also I really recommend taking a clock, or a little lamp or something, flick off the breaker, check the sockets, and so on just to make sure you are on a sererate breaker. They are usually marked wierd, and there will usually be one breaker with the sockets and all your roof lights as well.

Its wierd, all my breakers have a bunch of stuff on them, my kitchen counter has 4 plugs, each one on its own 15amp breaker. Electritians always do stuff differently, so its a good idea to be sure of whats what.