Dimmer switch help needed

[ThaiStyle]

Hi,

I've recently replaced a dimmer switch in our kitchen and I've either missed something or there is something 'unique' about the way it's wired up.

I've connected up C, L1 & L2 and earthed it. The dimmer works fine but...

We have a downstairs bathroom that is just behind the kitchen and the dimmer is located on the wall that separates the two rooms. Since replacing the dimmer, the lights in the kitchen and bathroom cannot be on at the same time!

In other words, if I turn the kitchen lights on, I cannot turn the bathroom light on. I have to first switch the kitchen lights off and then turn the bathroom lights on which works. However, if I switch the bathroom light on first and then switch the kitchen light on - the kitchen light comes on and the bathroom lights goes off!

Anyone have any thoughts on what I've done wrong here?

Thanks in advance.

Chris

 

[holmslaw]

..

 

[ThaiStyle]

You've mixed up the feed to the bathroom switch with the kitchen switchline.

Take the switch off and identify the permanent live and put it in C. Then put one of the other wires into L1, if the kitchen light works put the remaining wire into C. If the kitchen light doesn't work move the wire in L1 to C and put the remaining wire into L1.

I currently have red going to C, blue going to L2 and yellow going to L1. Which one is likely to be the permanent live?

 

[Taylortwocities]

Is there only one cable, with three wires going into that switch?
Can we see a picture?
Did you note what wires went where before you changed the dimmer?

Have you done any other work on the lighting circuit? ie changed other switch(es), a light fitting, etc???

 

[holmslaw]

..

 

[ThaiStyle]

Is there only one cable, with three wires going into that switch?
Can we see a picture?
Did you note what wires went where before you changed the dimmer?

Have you done any other work on the lighting circuit? ie changed other switch(es), a light fitting, etc???

Here's a picture.

No other work has been done other than change the dimmer.

Untitled

• ThaiStyle
• 5 Nov 2011
• 1

 

[Taylortwocities]

OK

There should be another switch that also turns those lights on and off. What are the connections to that switch?

 

[ThaiStyle]

OK

There should be another switch that also turns those lights on and off. What are the connections to that switch?

Not sure I understand your question...can you explain please?

 

[Taylortwocities]

Your switch appears to be wired up for two way working.
In two way working there are two switches that control the one light (like upstairs and downstairs switches for the landing light).

That is the usual reason to put 3-core and earth cable to one switch. The other end of that cable should appear at the other switch. Do you have a second switch, perhaps at the other end of the kitchen.???

If this is not the case then it may be that the red and yellow have other functions. To sort this, you will need to remember how the cables were wired on the original switch.
You did make a note of these, didn't you

 

[ThaiStyle]

Your switch appears to be wired up for two way working.
In two way working there are two switches that control the one light (like upstairs and downstairs switches for the landing light).

That is the usual reason to put 3-core and earth cable to one switch. The other end of that cable should appear at the other switch. Do you have a second switch, perhaps at the other end of the kitchen.???

If this is not the case then it may be that the red and yellow have other functions. To sort this, you will need to remember how the cables were wired on the original switch.
You did make a note of these, didn't you

Yes, as I said, the downstairs bathroom is on the other side of the wall so it seems as though the lights for the kitchen and bathroom are linked somehow (see my earlier comments above for more details).

I guess I may need to disconnect the cover for the light switch in the bathroom to see if this gives me some clues..

 

[333rocky333]

Do you have a picture of the back of the switch you removed to fit the new dimmer.
It may determine if its two way and may indicate the connections used.

 

[sparkwright]

Are you SURE you haven't replaced any other switches or light fittings in the house?

Was the old switch just one switch, or did it have two swithes?

Does the kitchen light work in conjunction with another switch (2 way)?

 

[sparkwright]

What's that other accessory next to the dimmer?

Looks like it could be a light switch.

What does it control?

 

[ban-all-sheds]

To sort this, you will need to remember how the cables were wired on the original switch.

You did make a note of these, didn't you

 

[ThaiStyle]

What's that other accessory next to the dimmer?

Looks like it could be a light switch.

What does it control?

It's another dimmer and controls a separate line of spot lights in the kitchen. This works fine and has not been affected by changing the other dimmer.

Unfortunately I no longer have the original dimmer and I did not make a note of the connections (yes, I know I should have done this).