Need help with wiring of new room stat please

[Arthur Daley]

Hello all, my mate has a crap looking stat in his new house and I said I would get him a replacement.

Anyway, below are pics of his old one followed by pics of the new one, but not sure where the third, Yellow wire goes to on the new one. Would like someone in the know to help me with this please :thnks:

 

[CoolHandLuke]

I believe it should run into number 5 or 6..........




Best wait for someone to confirm lol

 

[iHack420]

red is power white is common yellow is for your outside unit (a/c) should have instructions and be labeled w. for white g. for green. y. for yellow and r for red. it could be labeled L1 for power (red) and L2 or N for neutral (white) yellow doesnt matter unless you have an ac and in that case it would say ac or evaporate or outside coil. hope this helps.

 

[Him Her]

Ignore the previous post - this is the UK ffs...

To avoid sore fingers (or loud bangs) a meter would be useful - multi on 250V AC range is good. There's no wiring diagram with it? Looks like a standard stat with call neon.

You can ignore 5 & 6 if you don't want the pretty light to come on. If it's standard wiring then Red=Live, Blue=Neutral and Yellow=boiler trigger. So, Red to 2, Blue to 3 and Yellow to 4.

To test before you swap over:

Meter across red and blue to check for mains irrespective of stat setting. Then meter across yellow and blue and check adjusting the stat setting switches on and off.

If you want the pretty light to come on when the stat is calling the boiler then link 5 to 3 and 6 to 4. Before you connect up the pretty light check there are no links already (round the back) - should be just a little neon with a resistor in series...

 

[danforth]

Looked at this last night but didn't post. Had a few, so thought not wise. Having recovered (I think) today, still conclude

yellow should go on terminal 3, from comparison of old / new circuits.

Remarks about multimeter apply.

Please let us know which works, part curiosity, part sobriety test!

 

[Him Her]

So, you'd feed the boiler trigger with a neutral??? I think not...

 

[danforth]

So, you'd feed the boiler trigger with a neutral??? I think not...

Live goes to lever spring in each case. Boiler trigger (3) is the make contact in each case, so yellow.
Use rad stats myself so no experience, just going on diagrams. Could depend on whether thermostat contact is active make or break.
May have changed between models, wasn't arguing, just curious, hence request for feedback.
Will crow or cringe, depending on result !

 

[Him Her]

Live goes to lever spring in each case. Boiler trigger (3) is the make contact in each case, so yellow.
Use rad stats myself so no experience, just going on diagrams. Could depend on whether thermostat contact is active make or break.
May have changed between models, wasn't arguing, just curious, hence request for feedback.
Will crow or cringe, depending on result !

You could be right, but, according to the limited diagram, 3 is the bias resistor and the load (boiler) goes on 4...

 

[Arthur Daley]

Wow! I thought with just three wires this would be a piece of piss, but I am beginning to wonder :S

Although, I highly suspect that "H H" is right I think for my own peace of mind, i.e. I don't want to cattle truck his boiler, I may plump for the easier option of trying to buy an exact replacement from eBay and eliminate any possibility of it going Pete tong

However, If I find someone local to me in the mean time, who can verify the settings, I shall let you know the outcome.

 

[danforth]

You could be right, but, according to the limited diagram, 3 is the bias resistor and the load (boiler) goes on 4...

Don't know for sure do we ? A couple of minutes with a meter, or even neon screwdriver, would make all clear.

Juries out, need to wait until foreman returns (hopefully not laid out somewhere, no answers so far would do that).

May still trying to get the neon working ?

See he has, so no damage so far !

 

[danforth]

Wow! I thought with just three wires this would be a piece of piss, but I am beginning to wonder :S

Although, I highly suspect that "H H" is right I think for my own peace of mind, i.e. I don't want to cattle truck his boiler, I may plump for the easier option of trying to buy an exact replacement from eBay and eliminate any possibility of it going Pete tong

However, If I find someone local to me in the mean time, who can verify the settings, I shall let you know the outcome.

Good luck with exact replacement ! I find nothing new replaces anything old without head scratching.

Don't see how either option could damage the boiler though, one just won't work. Agree HH ?:questionmark:

 

[zad]

Boiler will have an inline fuse just wire it one way if it works it works if it don't fuse will go... then do it the other way

 

[Him Her]

Boiler will have an inline fuse just wire it one way if it works it works if it don't fuse will go... then do it the other way

Hahaha!

Connect the live and leave the other two off, turn the stat up fully and check which of 3 or 4 go live, turn the stat down to ensure it goes off, connect the yellow to that one. Ignore the neutral in that case.

Don't see how either option could damage the boiler though, one just won't work. Agree HH ?

Correct provided there's no override circuit (like frost protection) in which case when the override kicks in the fuse blows - boiler shouldn't be damaged in any case.

If that's a Robus RRF10 you won't need the neutral unless you want the pretty light on...

 

[danforth]

Hahaha!

Connect the live and leave the other two off, turn the stat up fully and check which of 3 or 4 go live, turn the stat down to ensure it goes off, connect the yellow to that one. Ignore the neutral in that case..

Good idea ! That should be foolproof even with just a neon screwdriver. I wonder if ?

 

[miggy]

Good idea ! That should be foolproof even with just a neon screwdriver. I wonder if ?

What a really good idea would be, Mr danforth is for the op to leave this job well alone and get someone in who is fully qualified and knows exactly what he is doing. If it goes pear shaped on the poor guy exactly who do we blame???. It's just my opinion guys better to be safe than sorry.

 

[danforth]

What a really good idea would be, Mr danforth is for the op to leave this job well alone and get someone in who is fully qualified and knows exactly what he is doing. If it goes pear shaped on the poor guy exactly who do we blame???. It's just my opinion guys better to be safe than sorry.

OP asked for help. I thought that's what the forum was for. Did I misunderstand ?

 

[miggy]

OP asked for help. I thought that's what the forum was for. Did I misunderstand ?

That is true the forum is for helping members however the OP should really consider the consequences should any problem occur. All I am saying is, he should seek more professional help if he has any doubts in performing electrical tasks that he is unsure of.

 

[danforth]

That is true the forum is for helping members however the OP should really consider the consequences should any problem occur. All I am saying is, he should seek more professional help if he has any doubts in performing electrical tasks that he is unsure of.

Agree in part, but as far as I can tell, he started before posting. There has been some safety advice, and the last I heard, he was considering
looking for an identical part. If he decides to get one, I don't think he will then decide to get professional help before fitting.
He has some experience and confidence, or he would not have started, so assistance seems valid to me.
If the only response to a request for help is "get a professional ", there seems little point in reply.

Your view, my view,-------------shall we let the op decide ?

 

[miggy]

If the only response to a request for help is "get a professional ", there seems little point in reply.

Your view, my view,-------------shall we let the op decide ?

2 pages 18 replies??? yes lets see what the OP decides. Get professional help is good sound advice in my opinion hence my reason for posting. In my opinion I think I have made a very good point.

 

[Him Her]

Now, now : mr ed :