Electrical test procedure on a gas boiler

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Theses test that I'm performing are standard tests that have to be preformed on a gas boiler before you service that boiler. The four tests to be completed are earth continuity, short circuit, resistance to earth and polarity. Three tests are done with the boiler isolated and obviously polarity is a live test. Theses tests are testing the boilers internal components and wiring looms within the boiler itself and not the source. Tests are being completed with a auto range multimeter.
and how do you do the psc, by calculation? I would do this as a live test, then refer tabular values and perform polarity whilst isolated and again whilst live. I would also be doing the Zs whist live, as you would need to test the Ze anyway which would again be a live test.
 
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Prentice Boy how do you test PSC, Zs or Ze? Do they need a meter?

Honestly a rhetorical question. When I was repairing the things I had, in van, meter capable of measuring these but if you could view some of the posts in Combustion Chamber (the closed gas forum) you would be surprised how many don't posess even a cheap basic meter, and those that do have no real idea how to use it!

The only boilers that the OP could possibly test in the ways he is suggesting would be 20 odd year old ones containing just the gas valve and a thermostat that are mains connected.
 
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Honestly a rhetorical question. When I was repairing the things I had, in van, meter capable of measuring these but if you could view some of the posts in Combustion Chamber (the closed gas forum) you would be surprised how many don't posess even a cheap basic meter, and those that do have no real idea how to use it!
When I last had my boiler serviced, I had to stop the gas chap (who had the kit, but seemingly 'no clue'!) doing a 1000V IR test on the boiler, which I suspect could easily have fried the electronics within it. He then refused to sign the certificate "because he had not been allowed to conduct all of the required tests" and I had to contact his employer to get this sorted out. I don't know whether they still employ him, but it unfortunately wouldn't surprise me all that much if they do!

Kind Regards, John
 
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gas chap (who had the kit, but seemingly 'no clue'!) doing a 1000V IR test on the boiler, which I suspect could easily have fried the electronics within it.
Yes almost certainly would have done! Scary really.

Did he work for a long established national company?
 
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gas chap (who had the kit, but seemingly 'no clue'!) doing a 1000V IR test on the boiler, which I suspect could easily have fried the electronics within it.
Yes almost certainly would have done! Scary really.
Indeed, and it was purely by chance that I happened to be 'looking over his shoulder' when he was about to do it!
Did he work for a long established national company?
No - a fairly long-established small local company. I may have been unkind to the firm in what I said before. The manager I talked to understood the problem, was very apologetic and rapidly got things sorted out (and even offered me a discount on my next service) - so maybe the culprit didn't stay in their employment for too long!

Kind Regards, John
 
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All martin has done, or is doing, is checking or testing the electrical connections to the boiler.

The results he has obtained (apart from the 17V) indicate that the circuit is as it should be.

Testing the boiler itself, for whatever reason, would be far more involved and would presumably be limited to whichever parts may be suspected to be faulty.
Should it (the boiler) be working as it should then there is no real point in testing it.


I am having great difficulty at the moment having a boiler repaired as none of the three engineers I have had seems to know how to cure it.
AllenE's comments may explain this.


how do you test PSC, Zs or Ze? Do they need a meter?
Yes you need a meter.
PEFC is the Voltage/Zs
PSCC is the voltage/Zn
PFC is the greater of the two
However, I do not think a boiler engineer would measure it except (he should) on initial installation.
 
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All martin has done, or is doing, is checking or testing the electrical connections to the boiler. ... The results he has obtained (apart from the 17V) indicate that the circuit is as it should be. ... Testing the boiler itself, for whatever reason, would be far more involved and would presumably be limited to whichever parts may be suspected to be faulty.
He said that the tests he was required to do included "earth continuity, short circuit and resistance to earth" ... "with the boiler isolated" (and just a polarity test 'live'). I assumed, perhaps wrongly, that this meant that he was undertaking these tests on the boiler side of the 'isolation'. Did you interpret his words differently?

Kind REgards, John
 
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I am having great difficulty at the moment having a boiler repaired as none of the three engineers I have had seems to know how to cure it.
AllenE's comments may explain this.
The problem is not a lot of gas engineers can be arsed with repairs, whether this is down to they is influx of them that do not have the knowledge to diagnose the fault or whether there is more money in condemning the boiler and swapping out, I dare not say!
 
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Prentice Boy how do you test PSC, Zs or Ze? Do they need a meter?

Yes a meter would be required.
I did add it was a rhetorical question as personally I do know how to do the tests (unless they have changed since I retired about 5 years ago. May well have done I admit).

Point I was trying to make was many gas men don't possess even a cheap multimeter and even those who do, have little knowledge of how to use!
 
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He said that the tests he was required to do included "earth continuity, short circuit and resistance to earth" ... "with the boiler isolated" (and just a polarity test 'live'). I assumed, perhaps wrongly, that this meant that he was undertaking these tests on the boiler side of the 'isolation'. Did you interpret his words differently?
Yes, that has reminded me he did say "at the boiler terminals".

However, same conclusion (nothing to do with the actual boiler).
 
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He said that the tests he was required to do included "earth continuity, short circuit and resistance to earth" ... "with the boiler isolated" (and just a polarity test 'live'). I assumed, perhaps wrongly, that this meant that he was undertaking these tests on the boiler side of the 'isolation'. Did you interpret his words differently?
Yes, that has reminded me he did say "at the boiler terminals". However, same conclusion (nothing to do with the actual boiler).
It surely might be? If tests on the boiler side of the isolation showed very low L-N, L-E or N-E resistances, that would surely most probably be due to "something to do with the actual boiler", wouldn't it? It could be that they are told to do such tests in order to avoid (reduce the chance of!) bangs (or clicks) when they energise the circuit.

Kind Regards, John
 
M

martineire

Lad the the problem I was encountering was only on the resistance to earth check Irrelevant as ye say it is I'm just interested in understanding why I was getting a resistance reading with the switch on. I'm not sure I still quite understand because I have the fuse removed from the spur so that's the live isolated from the main circuit. Now when I'm doing the resistance to earth test I am testing between Live and Earth. Now correct me if I'm wrong but as I understand by having the spur switch on but the fuse is still removed I have Neutral from the boiler connected to the main circuit but by having the switch off with fused removed I am now breaking the Neutral from the main supply, Correct??

Now this is where I'm getting confused. When I'm doing my resistance to earth test I'm testing between Live and Earth. Now I'm being told that I'm getting a resistance reading when the switch is on because the Earth and Neutral are connected at the meter so that is creating a circuit hence that is why I'm getting a resistance as opposed to having the switch off (neutral broken) and not getting a resistance (testing boiler only). But with the switch on and fused removed I'm probing the Live and Earth terminals at boiler, how is that creating a circuit through my multimeter regardless of the Earth and Neutral connected at meter because one my probes is in the Live terminal at boiler which is broken (fuse removed) and the other in the earth terminal but how is the creating a circuit through my multimeter so that I'd be is pick up a resistance?
Can one help me with this specific question?
 

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