LED Bulbs won't work together on same circuit.

[Fullerbull]

I have two lights on same circuit served by a single switch. Two filament bulbs work fine. One filament bulb plus one LED work fine in either position. Two LEDs will not light up (normally). If I switch on they momentarily light up, then go out, with one bulb nearest the switch going on and off rapidly. Very occasionally they will both come on when switched on (about twice in six last months). Also very occasionally (again about twice in six months)they will come on after many attempts in switching on and off. Anyone got any ideas?

 

[Leesparkykent]

Dimmer switch or normal switch?

 

[Fullerbull]

Normal switch.

 

[westward10]

Has there been any alterations.

 

[Octopus]

What happens if you put the filament bulbs back in?

what "type" of lamp fitting are they?

 

[ImpededLoop]

Are they 12V MR16 lamps?

 

[Richard Burns]

Are they 12V MR16 lamps?

Yes I am thinking an underloaded transformer.

 

[ImpededLoop]

Yes I am thinking an underloaded transformer.

That was my first thought too!

 

[JasperOban]

I agree with Richard, some transformers have a minimum rating. Are u using individual transformers for each lamp?

 

[Fullerbull]

Thank you guys for all your replies. There have been no alterations. Filament bulbs work fine either as a pair or if only one is fitted with the LED bulb( in other words in any combination, in either position, as long as one of the bulbs is filament). The bulbs I am using are TCP LED, 60W, Bayonet fitting, working off 240volt mains. I have tried re-seating the bulbs several times to check good contact in the socket. In any case there is always a good contact when an LED bulb is used with a filament bulb in the other socket!

 

[westward10]

Do these LED lamps operate okay elsewhere in the house.

 

[Fullerbull]

I have a similar arrangement in the kitchen which is adjacent to the room with the problem (study). In the kitchen I have the same set-up i.e. a single switch (non-dimmable)in a two bulb 240 v circuit. I use the same type and manufacturer LED bulbs, but the fitting is ES. The bulbs in the kitchen work fine (several months of operation) However, I don't think the type of fitting is the problem, because I can get the bulbs in the study to work, with no fiddling around trying to get good contact in the socket, provided one of them is a filament bulb - as described above. I am baffled!

 

[Fullerbull]

I have an upstairs bedroom, again with the same arrangement - One switch, two bulbs. The sockets here are bayonet. I can get the two LED bulbs to work in that bedroom no problem. However, I use filament bulbs there because the LEDs I have are too bright for a bedroom. I'll have to wait for them (filament bulbs) to fail then fit lower wattage LEDs.

 

[westward10]

Tis a mystery. Does it matter which holder you put the LED lamps in when you use one LED and one filament lamp.

 

[Octopus]

I swapped 2 bulbs between.2 identical fittings earlier this week... They both worked after they had been swapped, but only 1 before.

These were bayonet fittings!

Odd, but I put it down to crxp manufacturing standards of the bulbs.