Bathroom light turning off
October 10, 2014 11:06 AM Subscribe
You are not my electrician but I was wondering if you might experienced this problem. My bathroom has a fluorescent light with a pull switch and a ventilation fan that comes on automatically. I think they run off the same circuit. The light normally comes on fine but after a while- probably about half an hour normally- the light goes off.
The fan stays on until I pull the light switch again to turn it off. If I then try to turn the light back on, the fan will come on again but not the light. After leaving it for an hour or so, the light will come back on. This is not linked to whether or not the bathroom is steamy. We have changed bulb and light fitting. Could it be a problem with not enough current available to keep fan and light running? Any other ideas? Thanks!
The fan stays on until I pull the light switch again to turn it off. If I then try to turn the light back on, the fan will come on again but not the light. After leaving it for an hour or so, the light will come back on. This is not linked to whether or not the bathroom is steamy. We have changed bulb and light fitting. Could it be a problem with not enough current available to keep fan and light running? Any other ideas? Thanks!
Best answer: Oftentimes bath/fan light combos with a single switch have the fan part on a timer. Is it possible that someone has reversed the wiring so that the light part is on the timer and not the fan? Evidence pointing to this would be if the time until the light goes off is always the same.
posted by true at 11:17 AM on October 10, 2014
posted by true at 11:17 AM on October 10, 2014
Yeah, I was also wondering about the timer aspect of those kinds of switches in older houses. CAn you time it and see?
posted by poffin boffin at 11:28 AM on October 10, 2014
posted by poffin boffin at 11:28 AM on October 10, 2014
Response by poster: Flood- thanks. Wouldn't the ballast have been replaced when a new light fitting was installed? Our is out separate?
posted by KateViolet at 11:29 AM on October 10, 2014
posted by KateViolet at 11:29 AM on October 10, 2014
Generally, new light fixtures have new ballasts inside them. However, new ballasts can go bad quick, especially cheap ballasts like those found in inexpensive light fixtures purchased from box stores.
posted by Flood at 11:47 AM on October 10, 2014
posted by Flood at 11:47 AM on October 10, 2014
Does the light smell funny? When a ballast needs to be replaced, it emits a funny smell, almost like something plastic is burning.
posted by tckma at 3:08 PM on October 10, 2014
posted by tckma at 3:08 PM on October 10, 2014
Response by poster: There's no funny smell. I was intrigued by the timer idea. The light stayed on for about 58 minutes whereas I believe the fan has a timer setting of between 2-20 minutes so I don't think its that...
posted by KateViolet at 9:47 PM on October 10, 2014
posted by KateViolet at 9:47 PM on October 10, 2014
It could very well be a bad ballast but this is also typical of a loose connection in the fixture. Take the fixture down and check all connections even in the pull switch.
Basically how it happens is that fluorescent fixtures will have a heat limit that will shut off the light if it overheats. A loose connection will over time heat up as it arcs between the two wires. Check the connections and you should be back in business.
posted by wile e at 3:36 PM on October 11, 2014
Basically how it happens is that fluorescent fixtures will have a heat limit that will shut off the light if it overheats. A loose connection will over time heat up as it arcs between the two wires. Check the connections and you should be back in business.
posted by wile e at 3:36 PM on October 11, 2014
Response by poster: Follow up- true's answer came closest but for anyone else with this problem... The fan should be on a permanent feed that allows it to stay on for a bit even if the light is off then go off according to the timer. Also this means it can come on independently if it senses moisture. But the permanent feed had been connected to the light not the fan so the fan timer wasn't working properly. However, switching the feed made the fan work but light still goes off suggesting either electrician wired it that way to try to solve a fault not taking the lighting unit was faulty or he miswired It from the start and it has damaged the unit...
posted by KateViolet at 1:11 AM on March 15, 2015
posted by KateViolet at 1:11 AM on March 15, 2015
Response by poster: There was also an issue with the ballast!
posted by KateViolet at 9:17 AM on March 20, 2015
posted by KateViolet at 9:17 AM on March 20, 2015
This thread is closed to new comments.
posted by Flood at 11:10 AM on October 10, 2014 [4 favorites]