Is there an electrician in the house?

[swee'pea99]

Cooker hood, four little G4 halogen bulbs, all lasted maybe a year, three are still ok after two, but the other has been replaced maybe half a dozen times, the last couple after only four or five days. I'm always careful not to touch the bulb when fitting it. Any idea why this is happening, and/or what I can do to stop it? Any suggestions much appreciated.

 

[Paul.G.]

I've had exactly the same problem which I put down to crappy bulbs.

 

[slowmotion]

If the bulbholder contacts are slightly dodgy, the current to the bulb might be intermittent. This would cause the filament to heat up and cool frequently, even though the light output looks fairly constant. Filament lamps do not like thermal cycling.

My wild guess.

 

[swee'pea99]

If the bulbholder contacts are slightly dodgy, the current to the bulb might be intermittent. This would cause the filament to heat up and cool frequently, even though the light output looks fairly constant. Filament lamps do not like thermal cycling.

My wild guess.

Thanks. There do seem to be quite a few googled suggestions along those lines...I'm not quite sure how to go about cleaning the contacts - the holes are so small - but I must at least try. "Crappy bulbs"? Do they vary? I've always bought cheapos off ebay on the assumption that they're about as commodity as a product can get. Maybe I'm wrong...?

 

[the_mikey]

G4 halogen bulbs are super sensitive when Warming up or cooling down, the filament can also develop cracks that open up and break the circuit when warm, and the light goes out until it's cool again.

 

[slowmotion]

We had a couple of ceiling lights using GU5.3 lamps which always kept blowing. I changed the generic bulbholders and the problem seems to be cured. The problem with a cooker hood is that getting manufacturers' replacements will be ruinously expensive. White goods spares are an absolute rip-off. Try and find some generic ones.

EDIT: cross post with mikey. Good point!

 

[swee'pea99]

We had a couple of ceiling lights using GU5.3 lamps which always kept blowing. I changed the generic bulbholders and the problem seems to be cured. The problem with a cooker hood is that getting manufacturers' replacements will be ruinously expensive. White goods spares are an absolute rip-off. Try and find some generic ones.

EDIT: cross post with mikey. Good point!

Googling for some generic ones I came across these,

which claim to be special cooker hood bulbs - £9 a pop! As against 20p a go for the regular ones from ebay. And these, similar price, from Amazon:

Maybe they're for real. Maybe you do actually need 8/9 quid bulbs for a cooker hood. I suppose the only way to find out is to buy and try. £8!

 

[classic33]

Thanks. There do seem to be quite a few googled suggestions along those lines...I'm not quite sure how to go about cleaning the contacts - the holes are so small - but I must at least try. "Crappy bulbs"? Do they vary? I've always bought cheapos off ebay on the assumption that they're about as commodity as a product can get. Maybe I'm wrong...?

Wire wool & not from a brillo pad. Meths on a piece of tissue twisted so as to fit the hole to clean any grease out.

 

[slowmotion]

Googling for some generic ones I came across these,
View attachment 37809

which claim to be special cooker hood bulbs - £9 a pop! As against 20p a go for the regular ones from ebay. And these, similar price, from Amazon:

View attachment 37810

Maybe they're for real. Maybe you do actually need 8/9 quid bulbs for a cooker hood. I suppose the only way to find out is to buy and try. £8!

Buy the cheapies! The operating temperature of the filament of a tungsten halogen lamp is about 3000 degrees C. The elevation in operating temperature when in a cooker hood is absolutely trivial. Nice work for the cooker engineers.

My guess...

 

[swee'pea99]

Buy the cheapies! The operating temperature of the filament of a tungsten halogen lamp is about 3000 degrees C. The elevation in operating temperature when in a cooker hood is absolutely trivial. Nice work for the cooker engineers.

My guess...

Yeah - that was my thinking too...but the buggers will keep blowing! I'm going to try the cleaning route first and see if that helps. If not, maybe try an £8 one and see if it makes a difference. Thanks for all suggestions...much appreciated.

 

[classic33]

Check Tescos, the local one is selling those type of bulbs for pence, and their Philips not their branded ones.

 

[Globalti]

Sell that cooker and get an Aga. No electrics and a lovely warm kitchen.

 

[L14M]

Are you sure that you have gotten correctly rated bulbs?

 

[the_mikey]

Also grease that lands on the bulbs either from being fitted by hand or from anywhere else can reduce the lifespan of the bulb.

 

[subaqua]

Wire wool & not from a brillo pad. Meths on a piece of tissue twisted so as to fit the hole to clean any grease out.

NOT meths then which is residually greasy. Isopropylalcohol (IPA) cleans the grease away lovely. I used to cut an emery board to fit between the ceramics on linear Halogen fittings. vibration is the killer for lamps that are not cooled properly.