Yeah tried a kettle on it - it was fine
Sounds like it but, as the OP himself has said, the confusing thing is:I agree with PBoD, then - boiler.
About the only way I could rationalise that is if the boiler is, indeed, causing a leak to earth, but not enough in itself to trip the RCD (either of the RCDs, since they've been swapped without changing anything) but that there is enough 'other leakage' in other circuits protected by the same RCD as the boiler to bring the total leak up to the RCD's (either of the RCDs') trip threshold.what doesn't make sense is I plug the boiler into another socket (on a separate rcd connected circuit) and it doesn't trip. ... he's swapped the rcds between the 2 circuits - no change.
Sounds like it but, as the OP himself has said, the confusing thing is:I agree with PBoD, then - boiler.About the only way I could rationalise that is if the boiler is, indeed, causing a leak to earth, but not enough in itself to trip the RCD (either of the RCDs, since they've been swapped without changing anything) but that there is enough 'other leakage' in other circuits protected by the same RCD as the boiler to bring the total leak up to the RCD's (either of the RCDs') trip threshold.what doesn't make sense is I plug the boiler into another socket (on a separate rcd connected circuit) and it doesn't trip. ... he's swapped the rcds between the 2 circuits - no change.
Can you think of any other possible explanations?
andThe other circuit is not on the same RCD. To be honest I don't know if the other circuit is protected by another RCD -
he's swapped the rcds between the 2 circuits - no change.
So may I be!I've read it all again but may be confused.
I was initially confused/uncertain, on the basis of what the OP had told us, but the fact that we're now told that the electrician "swapped the RCDs between the two circuits" seems to suggest that the two circuits were, indeed, served by different RCDs, doesn't it?Have we resolved between:
andThe other circuit is not on the same RCD. To be honest I don't know if the other circuit is protected by another RCD -he's swapped the rcds between the 2 circuits - no change.
That's what I thought, but maybe the OP could confirm/clarify. I suppose that it's theoretically possible that there is a small leak (not in itself enough to trip an RCD) in the wiring of the circuit, even when no loads are connected, but enough leak from that plus (a leak in) the boiler (alone) to cause a trip?Plus, hasn't it been said that the boiler still trips both RCDs with nothing else connected to the original circuit?
I would think that if it were a circuit fault it would definitely result in a tripped RCD with a kettle plugged in.The electrician did say he found a leak between neutral and earth on the circuit hence he's returning to try and locate it.
Thanks for clarifying - that's what I thought.To clarify both circuits are protected by different RCDs (I just didn't know that earlier on in the thread).Suspecting a faulty RCD the sparky swapped them around. The problem remained. ... The boiler will only trip out when connected to a socket on 1 of the circuits. I have tried different sockets on the same circuit - it trips. When plugged in to the other circuit its fine. I have also tried unplugging all devices on the "faulty" circuit - it still trips.
It's certainly the only credible theory that I can currently think of. The N-E leak which the electrician found - was that in the wiring of the circuit (with all loads disconnected)? If so, that is very probably the underlying problem. In that scenario, although a small leak in the boiler might be enough to be the 'last straw' which causes an RCD to trip, it might not mean that there is anything wrong with the boiler - many devices/ appliances (particularly those involving electronics and associated power supplies) result in small leaks to earth even when they are 'working normally' and not faulty.I personally think Johns threory about there being slight faults with the boiler and the circuit sounds correct. The electrician did say he found a leak between neutral and earth on the circuit hence he's returning to try and locate it.
It depends upon the extent (impedance) of the fault, doesn't it? You seem to be thinking of a low (maybe even negligible) impedance N-E fault - in which case, as you imply, connecting almost any significant load (not just the boiler) ought to result in a trip. However, if it were a very high impedance N-E fault (only detectable by IR testing), it might never, in itself, be enough to result in an RCD trip, even if large (but 'non-leaky') loads were connected - but the RCD could trip if another load with a small leak ('the last straw') was connected.I would think that if it were a circuit fault it would definitely result in a tripped RCD with a kettle plugged in.The electrician did say he found a leak between neutral and earth on the circuit hence he's returning to try and locate it.
Not if it is a circuit N-E fault and a non-faulty boiler trips it then, surely, a kettle would.It depends upon the extent (impedance) of the fault, doesn't it?I would think that if it were a circuit fault it would definitely result in a tripped RCD with a kettle plugged in.The electrician did say he found a leak between neutral and earth on the circuit hence he's returning to try and locate it.
Yes, that makes sense and may, indeed, be the solution - but that would also be the case with just accumulated leakage without a circuit fault.You seem to be thinking of a low (maybe even negligible) impedance N-E fault - in which case, as you imply, connecting almost any significant load (not just the boiler) ought to result in a trip. However, if it were a very high impedance N-E fault (only detectable by IR testing), it might never, in itself, be enough to result in an RCD trip, even if large (but 'non-leaky') loads were connected - but the RCD could trip if another load with a small leak ('the last straw') was connected.
The N-E leak which the electrician found - was that in the wiring of the circuit (with all loads disconnected)?
Have we definitely determined that the boiler trips this one circuit with nothing else plugged in to it?
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