Shower Tripping Fuse/RCD

[Icebat]

I have a Triton Opal II 10.5kw shower, not sure how old it is (it was here when we moved in a year ago), which has three heat settings - a cold one, a medium one (one red mark) and a hot one (two red marks). In winter you need it on the hot one.

Anyway, this morning the shower cut out while in use, and when I went and looked the fuse on the consumer unit had tripped, as well as the RCD which I think protects that and a few circuits (everything except the lights, really). I switched them both back on and tested it again, and it works fine on the cold and medium settings, but instantly trips the two switches again as soon as it's turned onto the hot setting.

For some background information, Triton services replaced a heating element for me about five months ago. The shower has worked fine since then. I would think maybe it was the element again, but it's a bit different this time... last time, the shower still worked on the hot setting, it just wasn't actually hot (it was the same as the medium setting), whereas this time it just shuts off straight away.

Any ideas? Could a problem with the element result in a different behaviour like this, or is there anything else it could be? Also, just out of interest, since both the fuse and the RCD tripped - will one always cause the other to go?


I'm thinking it might be time to get a new shower, but I want to be sure it's actually the shower at fault first.

 

[KevinAllwood]

Hi, I would advise you to call out the engineer again if the element was just replaced 5 months ago. The fact that the RCD is tripping is a concern.

Regards,

KA

 

[PrenticeBoyofDerry]

I think you could start looking at the element, as heating elements when failing tend to trip the RCD, if the element is only 5 months old, there maybe a warranty still on it and if not you could always refer to the sales of goods act, with regards to having it replaced FOC.
If you have a mulit-meter it would be possible to test the heating element.

 

[Icebat]

If you have a mulit-meter it would be possible to test the heating element.

I do, I used it to test an oven element, but I'm not really familiar with showers at all - is it simple enough to do?


As for the warranty, I've had a look back and I'm confused. Triton sent me two emails when I booked the visit; the first had a pdf with T&Cs which said it was guaranteed for 90 days, the second had T&Cs in the email itself which said it was guaranteed for 12 months. The current one on the website says 90 days, but I guess I should be able to argue for the 12 months one...

I don't want to have to pay for it to be fixed, since then I'll have paid almost enough to get a new shower, without any guarantee that it won't just break again in six months time!

 

[PrenticeBoyofDerry]

I would ignore the 90 days and hold tightly to the 12 months, you will still have an argument with reference to the sales of goods act.

Test via multi-meter (M-M):
*Isolate shower prior to removing cover.
*Remove cover prove dead using AC volts on M-M
*Set M-M to ohms setting
*Test across neutral (blue/black) at supply terminal and at browns of tank elements.
*You would be looking for a reading of 12-18 ohms.

Will look for a vid for you.
Here we ago this should be helpful:
http://www.youtube.com/watch?v=wzPt1hsfVq4

 

[KevinAllwood]

If you open the shower unit and attempt any testing you will possibly make any guarantee worthless and give the company an out.

Regards,

KA

 

[EFLImpudence]

You would be looking for a reading of 12-18 ohms.

That's a bit high isn't it?

More like 5.5Ω.

 

[PrenticeBoyofDerry]

Ohms law would suggest the value stated by you is correct, but in reality the resistance is much higher.

 

[EFLImpudence]

I don't understand.

How then can they be 10.5kW with the same resistance (roughly) as a 3kW immersion heater?

When hot the resistance is going to be even more.

 

[ban-all-sheds]

5.5Ω is the hot resistance.

Cold will be about 5Ω.

 

[Icebat]

Thanks for the advice everyone! KevinAllwood is probably right, I think I spotted something to that effect in the terms of conditions.

But lets say hypothetically, if I did test it and got a reading from one element and nothing from the other, would that mean the element is definitely the problem?

If it is the element, I'm still confused about why it would have a different effect this time. Still, I guess I'll make an complainy call to Triton and hopefully it can be sorted.

 

[PrenticeBoyofDerry]

But lets say hypothetically, if I did test it and got a reading from one element and nothing from the other, would that mean the element is definitely the problem?

No, but it would be a good pointer that the element requires replacing if you get satisfactory readings, to the values I have previously post, then we can investigate further.

If it is the element, I'm still confused about why it would have a different effect this time. Still, I guess I'll make an complainy call to Triton and hopefully it can be sorted.

It may not be an identical fault, therefore a different outcome.