Monthly intermittent fault

[monkfish10]

I've been having this recurring problem where the RCD will trip (the MCBs don't move) causing power failure on everything in house. I can get everything (apart from sockets) to come back on immediately only if the MCB that controls the sockets is flicked down before I flick the RCD switch back up. The RCD will trip again if the sockets MCB is flicked up (even if everything in the house is unplugged and all the sockets switched off) until after several hours or longer - depending on how many attempts I've undertaken and their time apart - the sockets MCB won't trip the RCD and everything is back to normal......until the next invevitable power failure !

SOME DETAILS

-I live in a first floor flat house conversion
-Total MCBs are: lights, smoke alarm, cooker light, doorbell and sockets
-Power failures have happened at random times of day roughly one month apart
-I am almost certain that power failures happen when I am running hot water from the kitchen tap (activating the boiler), the other appliances tend to be plugged in but not being used at time.
-I have noticed suspiciously inadequete rewiring in the attic, where wires strewn across floor and not clipped on walls and some old wiring clipped off
-My landlord's eletrician thinks its a faulty appliance causing intermittent fault (is organising a PAT test on the appliances) but I think it goes deeper than that and is more likely to be either a faulty socket/faulty boiler/faulty wall wiring/faulty RCD that is causing the problem. I think I would have more frequent power failures if it was a faulty appliance because they are used so much.
-One time the lights MCB blew and became defective after a power failure which remains unexplained.


Given the information that I have listed, can anyone shed any more light on what could actually be causing the problem and give me any advice or information that will help me get to the bottom of this. I'm not an expert and I would like to be able to explain the situation in more detail as well.

Thank you

 

[DPG]

Sorry, didn't read it properly. Specsavers.......

It's not you - it did say that but he's edited it since! Daz

 

[sparksburnout]

Anyway, is it really likely that the OP will have enough computers or other leaky equipment in use? More likely a duff RCD, he needs to get a decent spark in to sort it. Landlords, in my experience, will get the cheapest nastiest excuse of a trades-person in whenever possible, and it is quite probable that the "Landlord'S electrician"(!!!) was the same guy as the plumber, chippie etc. In my experience most Landlords need sending into outer space.

 

[DPG]

Anyway, is it really likely that the OP will have enough computers or other leaky equipment in use? More likely a duff RCD, he needs to get a decent spark in to sort it. Landlords, in my experience, will get the cheapest nastiest excuse of a trades-person in whenever possible, and it is quite probable that the "Landlord'S electrician"(!!!) was the same guy as the plumber, chippie etc. In my experience most Landlords need sending into outer space.

I rent a house out myself so I am a landlord. Daz

 

[Marvo]

..........-I am almost certain that power failures happen when I am running hot water from the kitchen tap (activating the boiler), the other appliances tend to be plugged in but not being used at time.........

Is your boiler a gas one with electronic ignition/control board that requires power from a socket or fused switch?

 

[sparksburnout]

I rent a house out myself so I am a landlord. Daz

Well, I am sure, given your standing on here, that you are a decent bloke/landlord. Most, sadly, in my experience are not.

 

[DPG]

Well, I am sure, given your standing on here, that you are a decent bloke/landlord. Most, sadly, in my experience are not.

It's OK - no offence taken You're probably right. On both counts Daz

 

[Octopus]

Shame the OP can't post a picture of the CU.

But the way I read is is that the main switch is also the RCD - correct?

 

[Davisonp]

In simple terms, what is earth leakage? and why would it trip the RCD?

"https://www.youtube.com/watch?v=5hL13UjRSoY"

This video shows earth leakage from everyday appliances, and the front room of the house tested has a maximum earth leakage of over 3mA. A full house with washing machines, microwaves Etc can have too much natural earth leakage for an RCD causing it to trip occasionally.
Current regulations require newer appliances to restrict the earth leakage, where older appliances from before RCD’s were required on circuits did not have the same restrictions on earth leakage meaning some older appliances have greater earth leakage. Also, as appliances reach the end of their life, the earth leakage can become worse, so some older fridges can start triping RCD’s as the motor’s start to fail.

A 30mA RCD when working correctly should trip somewhere between 15mA and 30mA.

 

[Octopus]

"https://www.youtube.com/watch?v=5hL13UjRSoY"

This video shows earth leakage from everyday appliances, and the front room of the house tested has a maximum earth leakage of over 3mA. A full house with washing machines, microwaves Etc can have too much natural earth leakage for an RCD causing it to trip occasionally.
Current regulations require newer appliances to restrict the earth leakage, where older appliances from before RCD’s were required on circuits did not have the same restrictions on earth leakage meaning some older appliances have greater earth leakage. Also, as appliances reach the end of their life, the earth leakage can become worse, so some older fridges can start triping RCD’s as the motor’s start to fail.

A 30mA RCD when working correctly should trip somewhere between 15mA and 30mA.

Not sure I agree with this!

 

[sparksburnout]

I watched that vid, and then noticed this one https://m.youtube.com/watch?v=5CBuLHVxqLI. Good old Al, he's so busy saving money he's not noticed that great big yawning gap in the middle of his CU!! Hehe.....

 

[GETWIRED]

Had something a little bit similiar last week, the lady unplugged everytjing and the rcd still tripped. The boiler was fed off the sockets via a fused spur so she didnt unplug it when she unplugged all her appliances. Was a very slow leak on the water pump inside the combi. Maybe something to think about.