"I've got no hot water!" - Call out

[Jamie]

Got a call out today, No hot water, I get one of these call outs every couple of days, sometimes several in one day...

Turn up, Ask where the consumer unit is, water heater switch & tank is, go to the tank, take a look inside the cupboard and see a right state, electrical burning smell too...not a good sign to start off with haha, so back to the consumer unit and switch off so I can take the cover off and investigate...
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No flex grip resulting in the Neutral being pulled out of it's terminal (I don't know why it wasn't doubled over, so the terminal screw/plate gets a even hold each side like you would a bonding clamp)...

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Re bared the cable, terminated it and made sure it was all working ok, got a new flex grip out the van, couple of screws, got to nip back tomorrow with a new cover as we don't stock them! So put the old one back on for time being!

I've never seen a immersion heater thermostat housing that bad....to the point where the actual round cover melts..

Did a RCD test and all came back OK....So I suppose the neutral just didn't touch the earth/metal casing, as it never tripped of? I was wondering why the RCD was still holding for a start before taking the cover off, as soon as I opened the cupboard door I could hear it buzzing away :ears:

Just thought I would share that with you guys anyway, Anyone ever seen a worse thermostat housing?

 

[Richard Burns]

I have seen one just as bad, but the thermostat was melted as well because it was a loose line instead of neutral.

 

[Marvo]

Yep, typical of poor terminations on circuits that carry a reasonable current. It's not uncommon to see the lid or housing/enclosure melted as well as the insulation around the guilty termination.

You'll also com across similar damage inside appliances such as ovens or washing machines. Often they use those insulated blue ring terminals or lugs and they're only rated to 10 Amps. The uninsulated lugs are better and can carry higher current.

**edit** Nice clamp meter by the way, I wish mine was as clean and shiny as yours

 

[Jamie]

Thanks haha, It's only a cheap one (well free from the work store haha), comes with a leather case too about the only tool I have acquired and not bought