Problems with recessed lights

[Evergreen]

Hi All

The house I moved into recently has recessed ceiling lights in the kitchen. Two of these lights intermittently fail to come on or come on briefly and then go out. I've taken out the existing bulbs and cleaned their contact prongs because they looked corroded. I've tried brand new bulbs (halogen 50w GU5.3 12v). Nothing seems to achieve a permanent solution. I've Googled this problem but most of the solutions seem to suggest overheating which can't apply in my case because the lights are never on long enough. Can anyone suggest a possible answer, please?

Regards.

 

[tim]

How about the previous owner overheating them? Or maybe rodent damage?

Cheers

Tim

 

[DaveL]

I would agree with Tim, you need to check the wiring and fittings for damage.
Mice love pvc, no idea why. We used to have an old Anderson air raid shelter as a shed, lined with hardboard on battens, all of the wiring was behind the hardboard. Sometimes the fuses blow, while we were not using the shed, we replaced them and everything carried on working, until the light one end refused to work. On removing the hardboard we recovered quite a few dead mice, killed by chewing the pvc off the cable and shorting out to the steel wall of the shelter. :shock: We replaced a lot of the cable. :evil:

 

[RobertMP]

Having been manufacturing all kinds of commercial lighting for 30 years the answer to this type of problem is most commonly faulty lampholders.

The chinese lampholders on domestic 12V halogens are just not up to the job. We used german made lampholders and never had any after sales problems. With domestic LV downlights for sale at not much over a pound each you can see they will not be supplying the type of lampholder we did costing around £1.15 each to OEM.

A bad lampholder will ruin the lamp pins so if you change the lampholder change the lamp too. Buy some branded lamps off ebay - philips osram GE sylvania - not unbranded ones that produce less light and don't last as long.

Don't know if you can buy quality lampholders online. You may have to buy cheap ones or rob from new cheap fittings and just be prepared to change them next time you change the lamps...if not sooner.

 

[White House Workshop]

I'd agree with Robert. We had a similar problem with bulbs not coming on, only to find nothing wrong with the bulb itself or the wiring. Cleaning the bulb's contacts worked for a while only. Of course it's pretty much impossible to clean inside the sockets. We replaced the lighting set with a new one that had ceramic insulators instead of plastic and haven't had a problem since.

 

[Paul Chapman]

Interesting thread. I have several sunken lights in my kitchen. One refuses to work for no apparent reason and another plays up now and then. Maybe mine are the cheapo fittings as well :-k :-k

Cheers :wink:

Paul

 

[RobertMP]

Usually when the fitting is made of metal the intermittent ones are just an irritation. However they are intermittent because of a bad connection. Bad connections = heat and if the fitting is plastic could be a fire risk.
Commercial regs mean plastics are self extinguishing grades not sure they apply to domestics.

And just to add to the doubts... I'd never use the wirewound transformers that come with these sets. Modern electronic transformers have lots of safety features built in and are worth the bit extra.

 

[Loz_S]

I have had similar problems in the past and my experience is that the problem can nearly always be traced back to the wires. In my case the heat generated by the low voltage halogen spots had accelerated the oxidisation of the copper inside the cables. You can tell by pulling out a length from behind the spot, if it has gone hard then you need to replace the cable for a better quality, heat resistant wire. The space behind the spot in the ceiling space needs to be really quite large to prevent excessive heat build up. The lighting becomes intermittent because the conduction path through the wire becomes smaller as each copper strand oxidises. Cut a faulty wire open and you will probably find that it is green along quite a long section.

 

[Evergreen]

Many thanks for the helpful suggestions, guys.

I've checked the wires and they still seem flexible and I can't see any manufacturer's name on the lamp holders themselves. However, it would be entirely consistent with other things I've found in this house if the problem was caused by cheap 'n' nasty lamp holders. The previous owners were past masters at cutting corners and using the very cheapest, flimsiest materials, components, paints and fitments of every kind. We all like a bargain but these people were just foolhardy.

Regards.

 

[Keith Smith]

Another consisderation is overated transformers, I've seen two 50W lights run off one 60W transformer when originally it probably drove two 20W bulbs. It causes the same problem you are experiencing as the overload will keep tripping and is the next thing to look at if the wiring is sound.

Keith