Immersion tripping RCD

[coldyron]

HIi guys,

Had a call out to a property today and looking for a bit of advice. As stated the RCD trips whenever the immersion heater kicks in.

I have disconnected the incoming cables and Insulation Resistance tested them and they come out >200MOhms which is all good.

The element is a Theeta WT7 and the RCD trips whenever this reaches set temperature.

When i disconnect the earth from the immersion it holds and when I link through the element it holds. It's only when I introduce an earth that the RCD trips.

Am I missing something really obvious? Or is there something I've failed to do? I hoped it'd just be the element but the problem occurs when it's been linked through which is bugging me.

I want to be able to say I've taken it as far as possible until the plumber is back from faking sickness!!

I've tried to attach some pics of the issue.

 

[telectrix]

total guess work until you've IR tested the element. could be breaking down when hot.

 

[MDJ]

When i disconnect the earth from the immersion it holds .

Gasp, you didn't let your customer have a bath at the Time did you?

 

[Pete999]

When you say kicks in do you mean as soon as it calls for heat? if so the probably the element is kaput, finito, up the spout

 

[micknew]

The tank looks a though its been soldered around the element boss to stop a leak.
Advise customer that you are not responsible if it leaks after replacing the element.

 

[telectrix]

and what. pray, does it have anything to do with a wet-pants? ain't you got trouble enough without?

 

[coldyron]

Gasp, you didn't let your customer have a bath at the Time did you?

Unfortunately the house is empty at the moment so no shocking bath times for anyone!

Why is it still tripping the RCD even with the element linked through? That's what was confusing me. Made me think it was an internal issue which may be beyond me if I'm honest.

 

[telectrix]

what do you mean by linked through? if the element is duff and still connected then it will still trip.

 

[Hawkmoon]

hmm looks like the tank has got to come out for that imm change - certainly looks tight

 

[HandySparks]

The element is a Theeta WT7 and the RCD trips whenever this reaches set temperature....

... I hoped it'd just be the element but the problem occurs when it's been linked through which is bugging me.

The item marked Theeta WT7 is the thermostat, not 'the element'.

When you say that you've 'linked through' the element, what do you really mean?

Why did you IR the cables, but not the heating element?

 

[MDJ]

The item marked Theeta WT7 is the thermostat, not 'the element'.

When you say that you've 'linked through' the element, what do you really mean?

Why did you IR the cables, but not the heating element?

Ay Up fella, hows you doing?

 

[7029 dave]

That cylinder round the boss is knackered, would not even try and take that element out!! wet pants on the cards lol.

 

[Hawkmoon]

When the plumber returns from his sicky tell him the element's blown - when he changes it have a look at the blown one - all will be clear.

 

[HandySparks]

Ay Up fella, hows you doing?

Just fine, thanks. Been out to look at some church lighting.

As usual, Tel has got there first!

 

[Hawkmoon]

That cylinder round the boss is knackered, would not even try and take that element out!! wet pants on the cards lol.

Be alright - bitta boss white

 

[coldyron]

I feel like a complete doughnut. I googled Theeta W7 and the first thing that came up was "heating element". I wrongly assumed it was some sort of element and stat in one.

Numpty :banghead:

 

[Rampantchilli]

That cylinder round the boss is knackered, would not even try and take that element out!! wet pants on the cards lol.

and whats wrong with just cutting in a new boss at the bottom, and fitting a 14" elephant

 

[telectrix]

thought elephants were a bit more than 14". more like 14'.

 

[7029 dave]

and whats wrong with just cutting in a new boss at the bottom, and fitting a 14" elephant

Nothing wrong with that the good old Essex flange, but would you bother by the state of that cylinder?.

 

[richy3333]

As an aside... I had an element that kept tripping after a board change - RCBO board for an old 3086 job. Scratched my head and tested everything. Cable, element etc all OK. It was only after the circuit was in pieces that I realised that I had fitted a 6A RCBO rather than a 16A. What a donut!