Electric Boiler tripping off RCD?

https://www.youtube.com/watch?v=D5JicsXrQoY
Some information here may help, your gas safe engineer should have been able to resolve issues, most likely to be the heating chamber, where the element is housed, the heating system will be under water pressure, so isolate the boiler from both Mains electricity and close flow and return valves at the boiler and if need to replace the element then draining of the boiler will be something a gas safe engineer can perform, isolate the wires to the heating element and check with his multi meter for any leakage currents between Live and Neutral electrodes to earth, so if they can check the resistance on mustimeter between these electrodes to earth, which should be extremely high in excess of 20 Mega Ohms, if it is down to a few kilo ohms or even less, then you need to replace the element or possibly the whole heating chamber.
Quite an easy job for someone with knowledge of boilers and electrics. So check on You Tube videos type Electric boilers.
Please can you state the boiler brand name and model no

Testing with a multimeter, typically 9v or far less may show several meg ohms but it’s far more likely to breakdown at operation voltage 230 * 1.414 peak.

As registered sparks of many years as well as a portfolio landlord I get phone calls about rcd trips at least once a week.

My advice is always the same- 99% of rcd trips are earth-neutral faults occurring inside a failing appliance. Last week I talked through a diagnosis with a potential customer (I say potential as I'm not such a grabber to go and charge a call out for an easy diagnosis- much criticised by my peers for this approach) and we worked out within 10 minutes to be the microwave at fault. I've had it all- washing machines, tumble dryers, central heating pumps, oven elements, microwaves, kettles, gas combi boiler fans, central heating 3 port valves, hobs and more.

We're electricians. We deal with your fixed wiring. We are not multi-appliance service engineers.

So my advice is to ignore any advice on here to call an electrician- they will be able to diagnose you have a fault, tell you that you have a faulty appliance and tell you to get a suitable appliance repair man- and charge you for the diagnosis of course!

If you know its the boiler thats at fault then my advice would be to google up or contact the manufacturer for a suitable boiler service engineer.

Hope this helps

Yes Chris i know where you are coming from, it would be beyond the technical ability of OP to understand, as these are not electrical forums, so much rather not debate about when you have to use a megger and when a normal multimeter can suffice, I have both.

Reply to the comment left by Chris Byways at 08/02/2022 - 16:41

For OP : Please Look for the boiler manufacturers telephone number and get from them a number for one of the engineers who can look at it.

Hi,
Firstly, find out the manufacturer and model, get the Manufacturers Instructions from the Internet.
Secondly, find a competent person to deal with it, not the local sparky.
Having said that it WILL be the element, common causes of Rcd tripping. Replacements are specific to the appliance, not simply a Toolstation job.
I am an NICEIC approved contractor and a Gassafe registered engineer.
Get the right person and all will be well, anyone not sure how to test a heating element should not be considered.
Stephen

Sound like the total capacity of your incoming electricity may be the issue. Or could be that the RCD for the boiler has other sockets etc on the same circuit. Get an electrician to come take a look, and you may need to upgrade the consumer unit, put the boiler on 1 RCD and the others sockets on 1 or 2 RCDs depending on the size of the property

Reply to the comment left by moneymanager at 08/02/2022 - 13:00
Very well said.
But finding competent people is a matter that I have found increasingly difficult to address no matter how much you are prepared to pay. This systemic problem has been totally out control for decades and it is getting worse.
I have just had, to my knowledge, some 20 men and at least 16 vehicles, most of which have been lorries, involved in a water leak. I explained to most of them exactly where the leak is. Collectively and individually they have produced absolutely no productive output beyond agreeing that I am almost certainly right in my diagnosis and they are going to do nothing about it. It's down to me to fix their previous repair and their excuse for the failure is that they did not know that the previous repair would fail when they did it. That's the bottom line. You can argue the toss all day, or for months in this case, and you will get absolutely nowhere.
There is absolutely no continuity of task or management worthy of the term.
Empty headed slaves following process created by psychopaths.
Current estimate (Calculated by myself as nobody else takes any responsibility for this) for a one person property for water per year is over £1,400! The prediction from the combined input from the labourers and the "help desk", based on previous years of experience and water readings is that this will only get worse.
They have pointed out that should I decide that the leak is beyond economic repair that is fine as long as I keep paying the bill.
I have countless such stories in every "trade" over decades of direct experience and the situation is systemically worse now than ever.
Competent people are very difficult to find and they do not stay that way. Something eventually happens in their lives which undermines their previous ability to deliver.

Thank you all so much for your responses - every advice provided and experience shared is most helpful. To clarify:

1. Our electric boiler is on it own circuit with RCD in consumer box, so it doesn't shared with any other appliance or sockets or lighting..

2. Our electric boiler is Gabarron Mattira Mac 15, manufactured by Elnur, headquartered in Madrid Spain. Has any one had any experience with this supplier / boiler ?

3. We contacted Elnur uk for help and was given the contact detail of a business set up three years ago by an ex-employee of Elnur uk. Elnur UK doesn’t have its own customer-service engineers.

4. We have made appointment with the company suggested and hope they can solve our problem.

Spacial thanks to:
@ moneymanager: your experience resonates with ours: it is hard to find a heating engineer that thoroughly versed with “wet electric” and electrician that is well experienced with heating system.

@Timmo, noted about possible heat exchanger replacement, thank you. We have to bite the bullet if it is the problem.

@Smartermind, our boiler has its own dedicated circuit - not sure about whether the circuit has a dedicated RCD though. The circuit is dedicated to the boiler which powers underfloor heating (on separate circuit).

@Chris Byways, electrician tested the boiler and oked it but he is not familiar with electric boilers. I am afraid the rest of your response is beyond my comprehension, but I will mention to the ecogenie people when they come.

@ Mike, the link is very useful - I am really surprise how limited number of electric boilers are being in use. I have contacted the Elner UK and have been in touch with the people they suggested - hopefully this will lead to a satisfactory result.

@Paul Landlord, thank you so much - we have decided to do just as advised.

@ Stephen Smith: thank you for your clear guidance. Do you happen to work in Central London area?

@David Judd: the flat is only a small (36 sqm) one bed and has 11 circuits in the RCD consumer box, so I think every thing can be divided into different cuicuit has been divided, i.e. literally every appliance has it own circuit.

@ Paul Shears : thank you for sharing your experience, couldn’t agree more with your comment.

Thank you all so much once more and best wishes,

Xiaolei

By coincidence I had a problem with a commercial property yesterday afternoon, main RCD tripped even with all 50 circuit’s MCBs turned off. I suspected the RCD might be faulty, but had seen some rodent cable damage while clearing a loft. It was a simple wiring earth neutral contact. Called electrician at 4.40pm by 5.10 pm he had pieced out damaged wiring, and saved the restaurant’s evening’s business. £40 paid on the spot. Hope you get a good sparks!

Xiaolei, thank you for up dating us, I share your ordeal, I wish i could have helped .
You said you are based in Central London, where about in in Central London, nearest Tube station?
If you don't get any joy, try ringing various engineers and ask them specifically if they can fix your boiler, ask them if they have enough experience, a highly competent gas safe engineer who possesses good electrical/electronics knowledge would be able to fix the problem on your boiler, provided spares were readily available. Overall principle is very similar, a decent competent gas safe engineer should have no problem resolving the issue, long as he also possess electrical/electronic knowledge.
I downloaded Installation manual on your boiler, and interestingly it has two seperate heating chambers from the looks of it, one for Central heating and the other for Hot water pressurised system with a hot water 50l storage built in tank, each heating chamber has 6 elements of varying wattage of 2kw and 3kw, elements.
So if you had an electrical engineer attend , he could have part isolated the problematic element such that you would have got most of your heating and hot water still working, the most you would lose out is 3Kw of heating power out of 15Kw available to you,
So all your electrical engineer had to do was to isolate one element at a time from both Live and Neutral one element at a time and when the earth fault disappears, he can leave that element isolated and allow the rest of the boiler to continue to work on at the most 3kw less heat power, it would still heat your house to full temperature but may take a bit longer, and same goes for the 50l hot water reserve tank it would still heat it to required temp but may take a bit longer than before, at least you would not have got unstuck altogether, he could leave the wires taped up safely.
Please ask your electrician if he can do this then have a go, it should stop tripping if you isolate the defective element without disturbing any water works. Its something one can do as an emergency rescue before a new element can be purchased and or a complete new chamber replaced but that would mean draining the boiler and may cost far more.