Buzzing Dimmer - Most Likely cause?

ChilliBob

Hey everyone, 

We have a ceiling light which uses g4 bulbs. It has capacity for 9 of them, alas, only 4 are working.

The light switch is a dimmer, when twisted the lights do dim or brighten, however, a buzzing can be heard and after a while the lights do go off. 

I'm thinking the culprit is one of three things, but I'm not sure what is most likely..

A. Incorrect dimmer - not meant for LEDs
B. Incorrect bulbs - non dimmable perhaps (but would they even dim?)
C. The fact that more than half of the bulbs aren't working - a combination of gaps, broken ones and blown ones.

I'm looking to rectify this but not sure the most likely culprit, any thoughts much appreciated! 

diveunderthebonnet

Did it work ( not buzz ) when all the bulbs worked?

ChilliBob

diveunderthebonnet said:

Did it work ( not buzz ) when all the bulbs worked?

I don't know! We've been in this house for four years (yeah, I know, should have sorted if earlier!) and it's always been like this, so not sure on the full bulb scenario. 

On-the-coast

I dislike both g4 bulbs and dimmers… can’t imagine how tricky it would be to maintain a set of 9!

12v or 240v?
led or halogen?

either way you require bulbs that match both your transformer (if not mains as is quite likely with g4) and your dimmer.  They are very prone to buzz if yiu get it wrong. 

Start with a complete set of matching new bulbs - and buy double the number yiu need to allow for future breakages.  

clive0510

Surely an electrician would sort that. 20 mins job done I would of thought.

Brie

We had dimmer switches in 3 rooms and the lights never worked properly.  They'd pop when you turned on the lights, flicker, flat out stop working after 2 weeks etc.  Finally talked to an electrician who said it's common with the new energy efficient bulbs that are on sale as the dimmer switches aren't capable of handling them properly.  Took him about 30 minutes to sort out all three and we've not had a problems since.  7 years of problems and 1 year now of things working properly.

ChilliBob

On-the-coast said:

I dislike both g4 bulbs and dimmers… can’t imagine how tricky it would be to maintain a set of 9!

12v or 240v?
led or halogen?

either way you require bulbs that match both your transformer (if not mains as is quite likely with g4) and your dimmer.  They are very prone to buzz if yiu get it wrong. 

Start with a complete set of matching new bulbs - and buy double the number yiu need to allow for future breakages.  

I can read 240v 20w max on one of the bulb holders. I don't know whether the bulbs are halogen or not (I hope not!) at a guess they've been in for 10 years plus (we've been here for four, previous occupants redid it and we're here for 14). I'm guessing they're too small to out out any real heat to tell if they're halogen? Anyhow, I'd obviously replace with LED so perhaps that doesn't matter. 

Yeah, every other bulb in the house is Hue now, so I dislike these too! It's quite a large chandelier type thingy that looks alright, weighs a tonne and we don't use it too often (front room, evenings only, tend to have lamps) but it bugs me that it's not right (obviously doesn't bug me too much or I'd have sorted it out before 4 years!) 

ChilliBob

Brie said:

We had dimmer switches in 3 rooms and the lights never worked properly.  They'd pop when you turned on the lights, flicker, flat out stop working after 2 weeks etc.  Finally talked to an electrician who said it's common with the new energy efficient bulbs that are on sale as the dimmer switches aren't capable of handling them properly.  Took him about 30 minutes to sort out all three and we've not had a problems since.  7 years of problems and 1 year now of things working properly.

That's encouraging - we have an electrician round later in the week for other jobs - hence me basically looking over all the electrical bits I'm thinking of. I know there's this whole leading edge stuff when it comes to dimmers. I replace any other dimmers with on off switches and hue bulbs (and most often hue dimmers) but can't here! 

ChilliBob

clive0510 said:

Surely an electrician would sort that. 20 mins job done I would of thought.

Yeah, I'm hoping so, but I wanted to know if it was more likely a dimmer or bulb issue I guess, in hooe I could get what he needs before he comes

ChilliBob

I have a sneaking suspicion it might be a double whammy - non dimmable bulbs being used, and then I'd find the dimmer is an oldskool one! 

WIAWSNB

ChilliBob said:

Hey everyone, 

We have a ceiling light which uses g4 bulbs. It has capacity for 9 of them, alas, only 4 are working.

The light switch is a dimmer, when twisted the lights do dim or brighten, however, a buzzing can be heard and after a while the lights do go off. 

I'm thinking the culprit is one of three things, but I'm not sure what is most likely..

A. Incorrect dimmer - not meant for LEDs
B. Incorrect bulbs - non dimmable perhaps (but would they even dim?)
C. The fact that more than half of the bulbs aren't working - a combination of gaps, broken ones and blown ones.

I'm looking to rectify this but not sure the most likely culprit, any thoughts much appreciated! 

G4s are, what, 12V? So the ceiling fitting will have a transformer built in. 
Ideally you should check the trannie and confirm it's suitable for dimming, but chances are it will be. Any way to ID the make without removing it?
And these G4s - are you sure they are LED? All of them?
LEDs don't tend to fail, so the fact that only 4 are working in 9 suggests they aren't LED.
My guess is that the light fitting was originally designed for halogen capsules, and ditto the transformer. Therefore it isn't working correctly with LEDs.
It might work ok if you include one halogen amongst 8 LEDs, but that's obvs not certain.
What to do?
1) check the bulbs - confirm whether they are halogen or LED. If LED, remove one and check what writing is on it - take a pic with your camera and zoom in.
2) unscrew the dimmer from the wall and prise it away - take a pic of the info on it.
3) ideally remove the light fitting, and take a ditto of the trannie.