My bathroom light keeps blowing

[newbie123]

I have a Florescent - 2D 16W 2 PIN light in my bathroom. Which is in an enclosed unit like this:
http://www.thelightingsuperstore.co.uk/product.asp?productid=26526
http://www.thelightingsuperstore.co.uk/product.asp?productid=28558

It was installed before I moved in and worked fine for about 2 year. Then the bulb blew, so I replaced it, but now the bulb keeps going about every 6 months and it’s about £8 for a new bulb each time. The bulbs should last 10000 hour, but I’m getting no where near that. This is the 3rd time I am replacing it and each time with a good brand (Phillips, osram). Each time I replace it, one of the tubes light looks a bit burnt. I also tighten the screws as much as possible so that no moisture can get into the unit.

Any help would be greatly appreciated

 

[festa]

Get in an electrician if your not to confident about carrying out inspection work on your dwellings electrics.

BUT

If you are confident then...
Are there any other bulbs blowing on that particular circuit?
If not it could be down to either loose connections in the terminals in said circuit,now things to check....
1. turn off the MCB/pull fuse which protects the circuit your bathroom light is on and with a multimeter,check the circuit is dead then double check.
2. (im guessing) go up into the attic and check the cable which feeds the bathroom light ,if your not to sure on what cables should be there and how many then go see the WIKI at the top of the page.
3.Check terminals for loose connections and also look for any burning/charing at the terminals/cables.

Id say about 80% of these types of problems i go to are bad connections but if the connections seems fine then i carry out continuity tests (which you may be able to check depending on your tester) and insulation checks ( which i doubt you wont).

 

[Steve]

Do these fittings have a starter switch?

 

[newbie123]

Thanks for the help so far...

Yes it does have a starter (I think), but its an oblong one not the usual round ones that you get on tube lights. And it seems to be part of the enclosed unit and i have not been able to remove it.

No charing on any of the cables or connection, but the bulb itself is black on one side and smells burnt.

BTW: I forgot to mention last time that when it goes it just flickers alot but it is never totally off.

 

[dannyboi2003]

16w 2 pin 2D lamps have integral starters so when you change the lamp your changing the starter too. My guess would be the ballast is failing and is over-running the lamp causing it to fail prematurely, the ballast is probably the "oblong" thing you mention in your reply. If it were me i would replace the ballast but that depends on how easy its going to be for you to get a replacement and how confident you would be fitting it, its probably easier just to replace the fitting.

All the best
Dan