Which cables which?

[markyyyyyy]

I am replacing an old analog style satchwell Tsx 2356.

Just taken the unit off the wall and the cables behind are as follows:

Red
Yellow
Yellow / green
Blue

I'm assuming blue is neutral, yellow/green is earth , red is live? What is the yellow for?

Is this a switch live or something?

On the Honeywell DT90E I am installing, where does the red cable go and where does yellow go? I have put terminal block on neutral (blue) and just snipped and folded over earth.

Pic of the back unit of Honeywell one

Cheers

 

[CBW]

I’d say so, and generally yes (however colours mean diddly squat in a heating system). Can you test it/them?

 

[DetlefSchmitz]

Could you show us the picture of the original unit's connections before removal.

 

[markyyyyyy]

Thanks for replies.

Here is a pic before I took it out

 

[securespark]

Looks like blue is N, red is L and yellow is calling for heat.

 

[securespark]

Not sure if new stat needs neutral, though.

 

[mdbalson]

Red to A (Live in)
Yellow to B (Switched Live/Live out to heating)
Blue not required for new stat
G/Y not required for new stat
Put blue in a terminal block
Put G/Y in a terminal block