Replaced traditional lights with downlights - now wont work if lights in next room are on!

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Basildon_Bond

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Hi There,

I recently had a contractor come to replace the original central lighting cluster in a downstairs dining room with a set of six Kosnic downlights. He also replaced the original dimmer switch with a new compatible one, but found that the dimmer would cause flickering (due to some historical problem with the house wiring apparently?) - so replaced a module (in the dimmer) so it only acts on/off. Fine as wasn't too bothered about loss of dimmer function anyway.

Only just noticed however, that if I switch the existing lights on in the lounge, the new dining room downlights go off! Switch them off and the Kosnics in the dining come back on. I dont see any such effect with the traditional kitchen lights in the next room...

Any idea what might be going on here ?

TIA
 
without images , it maybe difficult to know exactly
maybe some sort of 2 way lighting on those switches

Before you changed the Module for the dimmer - DID everything WORK OK
 
ETAF said:
without images , it maybe difficult to know exactly
maybe some sort of 2 way lighting on those switches

Before you changed the Module for the dimmer - DID everything WORK OK
Click to expand...
Hi - yes it did. Sorry should have clarified the switches:

Original setup:

Lounge - a double dimmer switch; one for the ceiling lights, one for the side lights

Dining room - two separate switches:

1 - regular on/off switch
2 - dimmer switch


New setup:

Lounge - no change

Dining room - still two separate switches:

1 - regular on/off - this was unchanged
2 - new replaced dimmer switch - only... doesn't dim - only acts as on/off - cannot turn knob.
 
Should also add - just checked all the other downstairs switches - kitchen, utility room, hallway, outside light - a mix of on/off and dimmer - no effect
 
ETAF said:
Then if thats the case , maybe somehting you have done with the dimmer

did you take a note/photo of the all the cable connections before you made any changes ?
Click to expand...
As I read the original post ,the contractor changed the dimmer. You should get the contractor back. If they can't sort it ,demand a refund and engage someone else.
 
I would think he has assumed black is neutral, and it is not always neutral, and he has got the wires mixed up, so the lights are in series instead of parallel. This would also explain why the dimer switch did not work as expected.

With tungsten lamps, it would have been obvious, lights would have been dim, but the drivers in LED lights can correct for volt drop.

Personally, I would use whenever possible lamps with bulbs, so 5 years down the line, simple to replace a bulb, the idea of replacing the whole lamp seems daft. With bulbs easy to test, remove the bulbs, but with integral lamps, not so easy. However, seems no point saying how to correct the fault, as clearly the contractor needs to return and correct his error.
 
Very possible the dimmer is not compatible without the type of downlights.

The fault causing other rooms not to work correctly is likely to be;
1) at the light switch, depending how the house has been wired (hopefully it's here)
2) at a junction box in the ceiling directly above a downlight, depending how the house has been wired (still easy enough to find)

Are you getting this guy back, or are you going to do it yourself?

(If it helps, you can have dummy dimmers, which look like dimmers, but don't actually dim, and only act as a on/off switch.)
 
It is easy to make a mistake
1721036007108.png
the picture from Wiki shows how easy it would be to get one wire wrong, the junction box
1721037314966.png
that replaces the ceiling rose makes it easy, but often we find, the box comes with only three connections
1721037443697.png
and we need to add a fourth, just not British hay what?

So the question is are you calling the installer back to fix, recommended, or are you going to try DIY? If the latter, step one is photos, removing the ceiling lamp and looking behind it, and the switch. Remember, the wall switch may not isolate a lamp, so before removing needs switching off at the consumer unit. Since he has clearly not tested, he may have used other shortcuts, like not using a junction box, so need to be very careful when inspecting, there may be live wires you can touch.

Hence, best option, get him back.
 
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