Immersion heaters tripping

[TNDU]

Dynorod had come out to replace two immersion heaters and they did a very poor job. The power tripped when the immersion heaters were turned on so they said it was the wiring and we needed to get an electrician round to test the circuit. The electrician tested the circuit back to the consumer unit and said it was the two immersion heaters that Dynorod had installed which were faulty and tripping.

What could Dynorod have done that both of the two new elements are faulty? Is it possible for these immersion heaters to be faulty from new?

 

[sparxxxx]

Strange that you would have to replace 2 elements at the same time. I would bet there was nothing wrong with them and the supply is inadequate.

What sizes are the fuses/mcbs feeding the heaters? They should be 16 or 20Amp.

 

[ericmark]

What is tripping? MCB, RCD, RCBO?

 

[DetlefSchmitz]

What was the reason for replacing the immersion heaters?

 

[TNDU]

Strange that you would have to replace 2 elements at the same time. I would bet there was nothing wrong with them and the supply is inadequate.

What sizes are the fuses/mcbs feeding the heaters? They should be 16 or 20Amp.

only one immersion heater was working. the other one broke ages ago but we never bothered to call them out to fix it. so now that we have called them out they have replaced both.

i did check the power rating as i asked the dynorod plumber what rating the immersion heaters were and he said they were 2.4kw each and each are connected to a separate MCB, which is 16A each.

 

[TNDU]

What is tripping? MCB, RCD, RCBO?

the main RCD.

 

[TNDU]

What was the reason for replacing the immersion heaters?

as mentioned above because there was no hot water from the tank and so dynorod said the immersion heaters were broke. at that time, there was no tripping of the RCD, there was just no hot water. dynorod replaced the two immersion heaters and could not turn them on as the RCD tripped.

so I got the electrician round and he says the fault is with the two immersion heaters installed as he says "they were both shorting to earth". dynorod is coming to replace both immersion heaters again next week and if there is a still a problem i am not sure if i can find an electrician who can also do plumbing to look into get the immersion heaters working.

 

[sparxxxx]

the electrician round and he says the fault is with the two immersion heaters installed as he says "they were both shorting to earth".

Well that means they are faulty, unusual that the two new would both be faulty, but with factory sample testing it is possible to manufacture and issue a batch of faulty equipment. Wait and see what happens next week. In the mean time have you tried them individually?

And yes most electricians can replace immersion heaters.

 

[terryplumb]

Is your hot water cylinder unvented ,or vented ? Can you show pics ?

 

[ericmark]

The immersion heater is normally a mineral insulated heater, the mineral used is hygroscopic that means it attracts water, so if the seals at the end are faulty it will absorb water and have an earth fault, although they can be dried out, no point as they will just absorb it again, seems likely the seal not good to start with, or damaged in storage, however it takes time to absorb the moisture so could easy miss being found with manufacturers quality control, but the installer should have tested before turning on power anyway, so it is simply down to poor workmanship.

 

[TNDU]

Well that means they are faulty, unusual that the two new would both be faulty, but with factory sample testing it is possible to manufacture and issue a batch of faulty equipment. Wait and see what happens next week. In the mean time have you tried them individually?

And yes most electricians can replace immersion heaters.

it just seems odd that both immersion heaters would be faulty. as they are wired individually, they can be tested individually and they are both tripping the RCD when they are switched on individually. the dynorod plumber says they are brand new as i suspected he may have used second hand ones they had in stock but he says they are new. he has ordered two new immersion heaters and two new thermostats as he says the thermostats are wired seprately.

i can only think he may have damaged the immersion heaters or thermostats when he fitted them as it seems odd that both would be faulty from new.

or my electrician is dodgy and is telling me incorrect information. but i can't see why he would say the immersion heaters were faulty and not the fixed wiring as i would have paid him to fix the wiring, so it was not in his interest to say the immersion heaters were faulty as this meant he couldn't charge any more money.

 

[sparxxxx]

Is your hot water cylinder unvented ,or vented ? Can you show pics ?

Do they have different types of immersion heater?

 

[TNDU]

Is your hot water cylinder unvented ,or vented ? Can you show pics ?

i think it is vented. i don't have a current pic but this is an old pic

Do they have different types of immersion heater?

yes vented and unvented. the vented ones get the water from a cold water tank and the unvented ones get water directly from the mains.

i don't think the difference would have any signifance on my problem though?

 

[sparxxxx]

it just seems odd that both immersion heaters would be faulty. as they are wired individually, they can be tested individually and they are both tripping the RCD when they are switched on individually. the dynorod plumber says they are brand new as i suspected he may have used second hand ones they had in stock but he says they are new. he has ordered two new immersion heaters and two new thermostats as he says the thermostats are wired seprately.

i can only think he may have damaged the immersion heaters or thermostats when he fitted them as it seems odd that both would be faulty from new.

or my electrician is dodgy and is telling me incorrect information. but i can't see why he would say the immersion heaters were faulty and not the fixed wiring as i would have paid him to fix the wiring, so it was not in his interest to say the immersion heaters were faulty as this meant he couldn't charge any more money.

A lot of "qualified" tradesmen have nvq's, aka no viable qualifications

 

[sparxxxx]

i don't think the difference would have any signifance on my problem though?

Thats why I asked