Wiring replacement thermostat

[Naphta]

Trying to wire up a new Drayton RTS2.

My thermostat cable comes through as:

Red - Live

Yellow - Neutral

Blue - Neutral

Green/Yellow - Earth

I've tested voltage on the lines and validated blue and yellow are indeed neutral. I've wired it up as follows:

N - Blue

L - Red

CALL - Yellow

Earth - Yellow/Green

With the thermostat on the wall I get a red light but it makes no call to the boiler when moving the temperature dial.

 

[ProDave]

Why did you replace the thermostat? was it because it was not "working" perhaps there is a fault somewhere else?

It looks like you have probably connected it correctly.
 

 

[Naphta]

Old one didn't have any numbers on it.

Previous model was a 2 wire jobby with the blue taped up.

 

[Lurch]

My thermostat cable comes through as:

Red - Live

Yellow - Neutral

Blue - Neutral

Green/Yellow - Earth

I've tested voltage on the lines and validated blue and yellow are indeed neutral. I've wired it up as follows:

N - Blue

L - Red

CALL - Yellow

Earth - Yellow/Green

So you decided to connect live and neutral across a normally open contact?

Maybe yellow isn't neutral? Exactly how did you "validate" that you had 2 neutrals and a live? Why did you randomly stick wires in anyway even after validating that you don;t have the correct wires in the stat?

You need to test the wiring properly before you go any further, we're just guessing at this point.

 

[Andy™]

My thermostat cable comes through as:

Red - Live

Yellow - Neutral

Blue - Neutral

Green/Yellow - Earth

I've tested voltage on the lines and validated blue and yellow are indeed neutral. I've wired it up as follows:

your testing is slightly flawed... you havent identified your switch live... and you think something is a neutral yet your happy to just ram it into a live terminal...

 

[ProDave]

You clearly don't know much about electrics "Validate blue and yellow as neutral"? What did you test and with what?

If wired to conventional colours, blue would be neutral and yellow the switched live out. It's perfectly possible if the old thermostat was only 2 wire that the blue might not be connected to anything at the other end, and equally possible that your new thermostat won't work without neutral connected.
 

 

[Naphta]

So you decided to connect live and neutral across a normally open contact?

Maybe yellow isn't neutral? Exactly how did you "validate" that you had 2 neutrals and a live? Why did you randomly stick wires in anyway even after validating that you don;t have the correct wires in the stat?

You need to test the wiring properly before you go any further, we're just guessing at this point.

By neutral I meant 0v when tested against earth, I understood it to be the path for the live.

|-W-|-----/  ----|

N - L - 1 - 2 - 3

|      |               |

^ a rough translation of the wiring diagram on the unit.

I put blue in (N), red in (L) and yellow in (3).

Green/Yellow - 0v

Earth

Red - 240v

Live

Blue - 0v

Assuming neutral since it tested 0v against earth (and is the colour its supposed to be)

Yellow - 0v

Assuming it's the boiler wire because it wasn't taped up and not live.

 

[Lurch]

Assuming

So not "validated" then?

As I said, it needs testing and verifying by someone competent with the correct test equipment.

 

[rapparee]

http://s30.photobucket.com/user/ChrisPlumber/media/Acl-drayton-wiring.gif.html 

Look at this.

 

[ProDave]

With the new thermostat connected. What do you measure on the blue wire now? And the yellow wire when the stat is turned right down, and when it's turned up?
 

 

[Naphta]

Right so;

Red to Blue: 0v

Red to Yellow: 240v

Red to Green/Yellow: 240v

Blue to Green/Yellow: 0v

I can't say I know how to do a continuity test but that feels as though the neutral isn't working as it should be.

I know connecting that neutral is beyond what I'm comfortable doing but I just wanted some kind of help making sure I hadn't made some super stupid mistake.

 

[Doc Hudson]

By neutral I meant 0v when tested against earth, I understood it to be the path for the live.

|-W-|-----/  ----|

N - L - 1 - 2 - 3

|      |               |

^ a rough translation of the wiring diagram on the unit.

I put blue in (N), red in (L) and yellow in (3).

Green/Yellow - 0v

Earth

Red - 240v

Live

Blue - 0v

Assuming neutral since it tested 0v against earth (and is the colour its supposed to be)

Yellow - 0v

Assuming it's the boiler wire because it wasn't taped up and not live.

If using three core R,Y,B, then the conductor identification colours relevant at the time the cable was installed, would mean that neutral would be 'black' not 'blue'. without any other identification sleeve you would have to assume R,Y,B, could all be live conductors. The three core would be Brown, Black, Grey if Blue was neutral. I would guess that the blue wire may be just floating open circuit at both ends if you are not getting the relay to operate and complete the call for heat signal. What happens when you by-pass the thermostat and join Red and Yellow together? Will the boiler fire then. 

Doc H

 

[ProDave]

If using three core R,Y,B, then the conductor identification colours relevant at the time the cable was installed, would mean that neutral would be 'black' not 'blue'. without any other identification sleeve you would have to assume R,Y,B, could all be live conductors. The three core would be Brown, Black, Grey if Blue was neutral. 
 

In the RYB days, blue was a phase colour, but nobody had a "problem" using blue as neutral for thermostats and timer fans for instance, and it was VERY rare to find anybody sleeving the blue wire with black sleeving to show it was neutral.

Now we are Brown, Black Grey, most people think it is a sin to use black as neutral and we must use the grey.  A case of "what was right is not right now"

It puzzles my why we are stuck with 3 core cables that are all phase colours and very rarely used as such. for domestic work, a brown black, blue cable would make a great deal more sense.

 

[Lurch]

most people think it is a sin to use black as neutral

The NICEIC and 5WW's I think though.

I don't care what the NIC say, I am using black for neutral like a normal human being.

 

[Naphta]

If using three core R,Y,B, then the conductor identification colours relevant at the time the cable was installed, would mean that neutral would be 'black' not 'blue'. without any other identification sleeve you would have to assume R,Y,B, could all be live conductors. The three core would be Brown, Black, Grey if Blue was neutral. I would guess that the blue wire may be just floating open circuit at both ends if you are not getting the relay to operate and complete the call for heat signal. What happens when you by-pass the thermostat and join Red and Yellow together? Will the boiler fire then. 

Doc H

Boiler fires with yellow/red together.

 

[ProDave]

Right so;

Red to Blue: 0v

Red to Yellow: 240v

Red to Green/Yellow: 240v

Blue to Green/Yellow: 0v

I can't say I know how to do a continuity test but that feels as though the neutral isn't working as it should be.

I know connecting that neutral is beyond what I'm comfortable doing but I just wanted some kind of help making sure I hadn't made some super stupid mistake.

What do you get earth to yellow with thermostat at minimum, and earth to yellow with thermostat at maximum?

Also earth to blue with thermostat in both positions?
 

 

[SPECIAL LOCATION]

Boiler fires with yellow/red together.

If Red & Yellow joined fire the boiler then you must be missing a neutral to power the relay...

OR   red & yellow are reversed?

Your Instructions for  RTS2 state:-
 

IMPORTANT NOTE

RTS thermostats are ELECTRONIC with a relay output.

Unless connected to a 230V mains supply the relay will

not operate, no 'click' will be heard and the call for heat

contact will remain open.

see:- http://www.draytoncontrols.co.uk/sites/default/files/RTS 2 (I. Guide).pdf

IMHO.. you don't have a neutral at your thermostat.

Guinness            Guinness           Guinness

 

[Andy™]

I don't care what the NIC say, I am using black for neutral like a normal human being.

snap

 

[ProDave]

snap

Me three.
 

If Red & Yellow joined fire the boiler then you must be missing a neutral to power the relay...

OR   red & yellow are reversed?

Your Instructions for  RTS2 state:-

 

see:- http://www.draytoncontrols.co.uk/sites/default/files/RTS 2 (I. Guide).pdf

IMHO.. you don't have a neutral at your thermostat.

Guinness            Guinness           Guinness

I  suspect the neutral is not connected. Now if the OP would just come back with that voltage measurement I asked for in post ID 16 we would know.
 

 

[binky]

The NICEIC and 5WW's I think though.

I don't care what the NIC say, I am using black for neutral like a normal human being.

I stopped doing this a while back and sleeving black and grey appropiately - I find it useful as a reminder to myself to sleeve 2 conductors, like when a sleeve falls off