Installing a two way dimmer light.

[pneme82]

Hi all,

I am new to this forum and I need help installing what I believe is a two way dimmer switch. I have a single light bulb on the stairs which has a switch upstairs as well as two lights in the sitting room which are downstairs. Both the lights on the stairs and the two lights in the sitting room can be controlled via a double switch located downstairs. I removed the double switch and replaced it like for like with the new dimmer switch. Unfortunately, this didn't work as expected and the light upstairs doesn't fully switch off. The labels for the switch are as follows (pictures attached). I have also attached a picture of the new dimmer switch I bought.

Two way switch located downstairs :

Top section .... Common point (Red cable), L2 (Yellow Cable) L1 (Blue).
Bottom section.... Common point (Red cable), L2 (Black), L1 is empty.

Switch located upstairs for single stairs light.

Common point (Red cable)
L2 point (Yellow & Red cable)
L1 point (Black and blue).





View attachment IMG_20170903_110951.jpg

View attachment IMG_20170903_114950.jpg

 

[rpm2]

Try changing the bulb if it is an energy saving type.

 

[Toneyz]

I n your switch downstairs you will have a 3 core & earth cable,the earth should have a green/yellow sleaving over it and go to a earth terminal at the back of the metal back box, the red goes to common ,yellow to L1 and blue to L2.What wattage and lamp do you have in the light fittings ?

More importantly make sure that you isolate (turn off ) both/all lighting circuits or if in doubt the consumer unit main switch.

 

[telectrix]

as above posts, note that if the new switch is metal, then the cpc (earth wire/s to the layman) should be connected to the earth terminal of the switch as well as or instead of to the back box.

 

[pneme82]

Try changing the bulb if it is an energy saving type.

I am using a halogen like bulb which is similar to the one in my bedroom which works fine with a dimmer.

 

[rpm2]

I am using a halogen like bulb which is similar to the one in my bedroom which works fine with a dimmer.

Take it you haven`t tried then.
A dimmer or the same maker & model?

 

[davesparks]

Is the lamp you are using of greater power than the minimum load rating of the dimmer?

 

[Deleted member 9648]

Two way switch located downstairs :

Top section .... Common point (Red cable), L2 (Yellow Cable) L1 (Blue).
Bottom section.... Common point (Red cable), L2 (Black), L1 is empty.

I suspect you have assumed that the 'top section' and 'bottom section' are the connections for each switch.
In fact each switch has connections at the top AND bottom.
ie common at the top, L1/L2 at the bottom.
Although you state you have connected like for like if it doesn't work then clearly you haven't, it worked before.

 

[Wilko]

We are easily confused ... well I am at least
I'm just going to say it - please ensure that power is off before you touch any of that. If you are going to touch the wiring, I recommend you turn off the board at the main isolator switch. There can be more than 1 live circuit in those backboxes !

 

[Wilko]

Talking about confused - are you saying - the stairs light can be switched on /off from a single switch upstairs and one of the two switches downstairs? And the other two downstairs lights just switch on and off on the 2nd downstairs switch? And it's the downstairs two lights that you'd like to dim?

 

[Taylortwocities]

Just to be clear, Are you tring to put dimmers at both ends of this circuit? Or just at one end?
>you have to buy special dimmers if you want to do this.

Secondly. What are the terminal markings on the dimmer, what make & model is the dimmer.

 

[pneme82]

Just to be clear, Are you tring to put dimmers at both ends of this circuit? Or just at one end?
>you have to buy special dimmers if you want to do this.

Secondly. What are the terminal markings on the dimmer, what make & model is the dimmer.

Thanks for the reply. I am trying to put a two way dimmer switch downstairs. This

Talking about confused - are you saying - the stairs light can be switched on /off from a single switch upstairs and one of the two switches downstairs? And the other two downstairs lights just switch on and off on the 2nd downstairs switch? And it's the downstairs two lights that you'd like to dim?

That is correct. I am trying to install the dimmer switch downstairs and this has two dim buttons on it. One button should be able to dim the lights in the sitting room and the other should be able to also dim the lights on the stairs. I am not touching the switch for the stair case light which is also upstairs.

 

[Taylortwocities]

Ok

And

Secondly. What are the terminal markings on the dimmer, what make & model is the dimmer.

 

[Darkwood]

Just to save the confusion, I have deleted the other duplicate thread and brought the reply posts into this thread, just in case you were wondering where a few replies had appeared from

 

[Richard Burns]

So long as you have replaced the downstairs 2 gang switch by matching the cable positions into each terminal then this should be electrically correct.
However, often a light bulb that is low energy is less than 60W, even a halogen energy saver, and this would be below the rating of the dimmer switch (60W to 400W) which may cause the dimmer to malfunction.
Alternatively if the light bulb is an LED or compact fluorescent then there may be enough voltage on the cable to allow the light to flicker or pulse on even when the switch is off, although this may be expected to have been noticeable without the dimmer switch as well.
Possibly the dimmer switch for the landing light is faulty and is not making the final switch off when switched and remaining at minimum brightness.

 

[Wilko]

OP - did the dimmer for the two lights in the sitting room work as expected?

 

[Rpa07]

I'm not stating the blooming obvious when I say 'if the dimmer is a push to off, have you pushed to off?'
If you have turned it right down to the lowest glow but don't push it to off then it'll keep glowing!

 

[pneme82]

OP - did the dimmer for the two lights in the sitting room work as expected?

Thanks for your help, this has now been resolved. Thanks

 

[Rpa07]

Uh hummm, details please @pneme82!

 

[westward10]

Maybe you were correct in #17.