Change T6360B for Salus RT200 - Help

[markvaughan]

Hi,
I'm finally giving in and asking for help on this.
I have a Honeywell T6360B - fairly common from the amount of reading I've done. Main source of advice was here;

http://www.dancingfrog.co.uk/posts/2013-08-24-honeywell-t6360b-thermostat-wiring
and this is a pic of my T6360B

1 - Live (Yellow)
2 - Neutral (Blue)
3 - Switched Live (Red)

The Salus RT200 has a nice backplate with good markings.

the problem;
When I wire up the back plate nothing happens. No call for heat, no light. The current programmer is an old Honeywell ST699 - due to be replaced with Salus EP200 after this is sorted.

I checked the control box, and it's not wired up like the Y plan in all the diagrams..

So the existing room stat is wired -
Live (Yellow) to 4 which is on an unknown cable.. goes down into the room with the boiler and the programmer.
Neutral (Blue) to 2 which looks like commons.
Switched Live (Red) to 5 which is connected to the white wire of the Valve.


So my question is, why does the old stat work and the new one doesn't when it's the same three wires?
The diagram I have says 1 should be the mains Live, so I guess the boiler is powered directly. There is an FCU in the wall, when I trip it the boiler shuts down.

Can anyone can offer some advice to get this working please?
I hope this is enough info to get started?

 

[PrenticeBoyofDerry]

Is this a stupid question?
Have fitted the front plate to the backplate?

On the link shown, the live and switch live are in different terminals.
Is your picture as it was originally installed?

 

[ban-all-sheds]

Nothing to do with the not working Q, but at the top of that wiring cintre you have a twin & earth cable with the earth core being used as a live conductor.

You MUST change that - if you need 3 cores + earth then you'll have to replace the cable.

Also, why have you drawn a red line over that cable (single core earth?) going to the cylinder stat?

 

[markvaughan]

Yeah, fitted the front plate to back plate..
And the red colouring on the cyclinder stat cable was just to differentiate it from the T&E next to it - because again it's just a 3 core flex.

 

[ban-all-sheds]

On the link shown, the live and switch live are in different terminals.

This:

1 - Live (Yellow)
2 - Neutral (Blue)
3 - Switched Live (Red)

matches this:

No?

 

[markvaughan]

Yes, matches and works fine. This is the old stat, wiring as I found it.
New stat doesnt work when wired up. The Salus RT200.

I dont know why a wire for wire, like for like connection to a new stat should fail.

 

[ban-all-sheds]

Yeah, fitted the front plate to back plate..
And the red colouring on the cyclinder stat cable was just to differentiate it from the T&E next to it - because again it's just a 3 core flex.

More badness, BTW - the G/Y core of that is connected to the black of the twin & earth.

I know you want to get things working, but you have a number of wiring issues far more pressing than that to sort out.

 

[markvaughan]

Yeah, bit of a joke right? All how I found it though, not my work.

Like I said, the Y plan diagram shows power should be fed to the control box and distributed out.. nothing connected on 1.. and the earth to the stat has no sleeve..

I will fix all the wiring issues, but any clue why this straight swap stat for stat doesn't work?

Just to reiterate - everything existing works. Turn up the stat - the CH fires up - the programmer set to constant CH.

 

[markvaughan]

More badness, BTW - the G/Y core of that is connected to the black of the twin & earth.

I know you want to get things working, but you have a number of wiring issues far more pressing than that to sort out.

like this..

I'm exchanging these junction boxes for WAGO lever connectors and boxing them up. The red cable at the top RHS was so burned up it's black in the photo.

 

[JohnW2]

...any clue why this straight swap stat for stat doesn't work? Just to reiterate - everything existing works. Turn up the stat - the CH fires up - the programmer set to constant CH.

The RT200 is functionally identical to the your present T6360B. If, as seems to be the case, you have correctly connected the N, L and S/L to the terminals on the backplate of the RT200, but it doesn't work (whereas the T6360B does), the only really logical conclusion is that your RT200 is faulty. Does it 'go click' as you turn its dial past room temperature?

Kind Regards, John

 

[markvaughan]

NO, there is not an audible click as it passes anywhere on the dial.

It's supposed to be electronic though? There is no access to the front of the unit, it only clips to the back plate, so I cant open it to see what's in there.

 

[JohnW2]

NO, there is not an audible click as it passes anywhere on the dial. It's supposed to be electronic though?

Although it's called 'electronic', the manual refers to the 'contact type' (which is simply describes as "Single Pole Single Throw"), which suggested to me that it has some sort of relay (which one would expect to go click or clunk, maybe quietly!) to do do the load switching (rather than an 'electronic' switch'). However, I may be wrong. In any event, there's meant to be an LED on the front which goes on and off as the dial is moved past ambient temp - so if that's not happening, either, again I would suspect the unit.

Kind Regards, John

 

[markvaughan]

ok..
I ripped the thing open.. pretty solid state..

looks like main dial is connected to a basic rheostat?

 

[JohnW2]

ok..I ripped the thing open..

Not necessarily such a clever idea if you may be trying to get it replaced!

pretty solid state.. looks like main dial is connected to a basic rheostat?

Indeed, but that thing at the top right on the back is a relay.

Kind Regards, John

 

[markvaughan]

Broken.. Now fixed.

Thanks for everyone who replied, I can get the rest of the wiring sorted out and get the new programmer in..