Frost Stat wiring

[bigGman]

Thanks to all for replies about my boiler packing in, now I have a new problem. in eliminating causes of my boiler not working someone suggested a possible cause could be the frost stat. I disconnected the frost stat. it turned out not to be that but a bust gas valve. however as you've probably guessed, in my haste I didn't make a note of the wiring.
Does it matter which way round the wires go? what will be the issue if they go back the wrong way round and what is the correct way round. its a Honeywell stat going to an Ideal Classic boiler.

 

[bengasman]

If it was a generic stat wired up correctly originally, it would not make a difference with most stats as they tend to be simple on/off switches.
The risk here is: it could be a non-generic one and it could have been botched when it was wired up. Would not be the first time that I found a cable coded for "earth" actually was live.
If you want to be safe, you need to find out if your stat is a mechanical switch, and how it is wired into the boiler.
You will have to assume you are working on 230V!

 

[bigGman]

2 core cable, one brown one blue, one goes to a live in the box the other goes to the switch. what would happen if the were wrong way around?

 

[bigGman]

If it was a generic stat wired up correctly originally, it would not make a difference with most stats as they tend to be simple on/off switches.
The risk here is: it could be a non-generic one and it could have been botched when it was wired up. Would not be the first time that I found a cable coded for "earth" actually was live.
If you want to be safe, you need to find out if your stat is a mechanical switch, and how it is wired into the boiler.
You will have to assume you are working on 230V!

How do you find out if it a mechanical switch???

 

[bigGman]

If it was wired up back to front, could it result in the room stat being bypassed and the heating staying on when the room stat was set to off???

 

[twgas]

if there are only 2 connections in the stat connect it to them, I suspect there are at least three, look inside the cover - it may show you which cons are which.

 

[bengasman]

Google brand and model number, or go directly to manufacturer's website and check. It is the only way to really be sure.
An installer who has seen a hundred of them could probably tell by just looking at the innards, and measure what goes in and out.
the problem with the wiring is that you don't know who dunnit and therefore you could connect 230V to a point where you don't want it if the connection was botched. I could not tell for sure about froststats, but I have found more roomstats wired wrong than, than wired right.

 

[bigGman]

Wiring in the stat hasn't been touched. It is the wiring where the mains goes to a switch then a two core cable goes to the boiler, a two core cable to the stat and two 3 core cables go off to I assume the room stat and the pump upstairs in the airing cupboard.
The stat was disconnected at this switch. so my question is, does it matter which way round i put them back??? and what will happen if I get it wrong????

 

[bengasman]

Doesn't matter if it is touched or not; you don't know it was ever correct in the first place.
What can happen? All those things that can happen when you stick a live 230V cable in the wrong place.

 

[bigGman]

It worked ok for the last 10 years so I assume it was wired ok in the first place

 

[bengasman]

Common misconception; the fact that it works does not prove that it works safely.
Compare to a car with bad brakes; when you find out about the faulty brakes, it is probably too late

 

[bigGman]

Common misconception; the fact that it works does not prove that it works safely.
Compare to a car with bad brakes; when you find out about the faulty brakes, it is probably too late

Not a very good analogy as were dealing with electricity. if something only goes one way and it works and putting it together the wrong way around has an adverse effect then it will not take ten years to figure that one out...

So back to my original question, assuming that for ten years the wiring was correct, what will happen if I change the wiring and wire the thermostat into the switch with the wires the wrong way around.

 

[bengasman]

Common misconception; the fact that it works does not prove that it works safely.
Compare to a car with bad brakes; when you find out about the faulty brakes, it is probably too late

Not a very good analogy as were dealing with electricity. if something only goes one way and it works and putting it together the wrong way around has an adverse effect then it will not take ten years to figure that one out...

Find out how ac works.
Then find out what a cpc is.
Then find out what can happen as a result of the various ways to botch a cpc.
Until then, just accept that the fact that something works, does not prove it is safe. If you don't like the analogy, ignore the analogy.
If you think you know better about electricity than I, you are free to experiment and get some empirical data.
As I feel generous today, I will give you another analogy.
A faulty foundation lived for 7 years before what was on it was reduced to rubble. I can't remember the exact address, but is was around the corner from the local kebabshop where I used to live.
I had a bit of a shock when I arrived to disconnect the boiler on the wall next to it.

 

[bigGman]

Once again in the seven years I'm sure that cracks did appear it didn't JUST fall down.
If I was a sage regarding electricity I would not be asking for advice.
I'm glad your feeling generous, I would just like the question answered and no more analogies. I get the safety bit and all that.
What I want to know is o never mind..........

 

[TonyW2]

Hi OP,
This is getting complicated and argumentative!

Your description is a bit lacking; originally you mentioned disconnecting the frost stat-- within that, just reversing the two wires across the internal switch would not be a problem (although always preferable to stick to the intended instructions) but it seems that is not what you meant. You say the disconnection is at a switch.When you refer to a switch do you actually mean a programmer/timer unit? If so, there are a multitude of internal possibilities and you will definately need the wiring diagram or somebody who knows the model. (If it is just a switch, with just an in/out wire across it the connections across it would also not matter, BUT I do not understand or recognise what switch would be in place.)