RCD keeps tripping (apologies for on-topic post;-)

All of a sudden our house RCD keeps tripping about every 5-10 minutes. It was fine for years. As far as I know nothing has changed recently. What is the easiest way to diagnose this without unplugging half of everything and keep this up until the guilty device is identified?
--
I am the God of Hell fire and I bring you: Brexit

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

“Divide and conquer” is the normal method but if it’s occurring as regularly as you say, I’d be wondering about something with a thermostat tripping it regularly.
Heating elements are common causes but it may be a fridge or freezer too causing the problem.
Tim
--
Please don't feed the trolls

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
In article

I had a similar problem here some 25 years ago. Lighting wiring in the celing getting very hot from the fitting below - so hot that the insulation was charred!
--
from KT24 in Surrey, England
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Wed, 15 Aug 2018 15:45:03 +0100, Mark wrote:

Something with a thermostat, like a fridge/freezer perhaps?
--
TOJ.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Wednesday, 15 August 2018 15:45:12 UTC+1, Mark wrote:

water ingress somewhere - leaky or overflowing loft tank near some wiring?

unplug half of everything and keep this up until the guilty device is identified :-)
Start with consumer unit and isolate circuits. Take the power circuits off first which will rule out the lighting. The slowly reconnect one at a time.
Owain
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Snag with that is most MCBs etc are only single pole switching. A neutral to earth fault can still take out the RCD.
Better to unplug things unless double pole switched.
Most likely IMHO is anything with a heating element of a certain type. Washing machine, immersion, oven etc.
--
*What was the best thing before sliced bread? *

Dave Plowman snipped-for-privacy@davenoise.co.uk London SW
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Wed, 15 Aug 2018 16:35:33 +0100, "Dave Plowman (News)"

FWIW I don't know what is double pole switched here.

Thanks to all who have responded to my post. At the times when it was tripping regularly the washing machine was on. Right now it's better (i.e. it's not tripped again for a while). In addition the washing came out of the machine much wetter that usual. Maybe it's a conincidence but .....
We don't have an immersion heater or a electric shower BTW. Our water is heated by a Combi boiler.
--
I am the God of Hell fire and I bring you: Brexit

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Also, given the change of weather recently, suspect any outside wiring, security lights etc.
--

Graham.
%Profound_observation%
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Wednesday, 15 August 2018 17:38:00 UTC+1, Mark wrote:

Insulation test all appliances with a multimeter. A megger or PAT tester is better but an MM will pick up the great majority of faults.
NT
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 15/08/2018 18:17, snipped-for-privacy@gmail.com wrote:

He doesn't know what 'double pole' switching is, so is unlikely to possess test gear :-(
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Fri, 17 Aug 2018 15:48:29 +0100, Andrew

I took it to mean he doesn't know which of his appliances had double-pole switching, on the basis that what you've suggested wasn't likely. BICBW!
--

Chris

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Correct.
--
I am the God of Hell fire and I bring you: Brexit

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

It means using two men called Lech and Waclav to turn the appliance off. :-)
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Friday, 17 August 2018 15:48:35 UTC+1, Andrew wrote:

Sure. Multimeters are a fiver or so, as long as it has a high resistance range it'll do the job. They have lots of other uses and will pay back the cost several times.
Yes you can try unplugging things but that frequently fails to find the problem & wastes a ton of time.
NT
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Rather depends on the age of the installation. Things like cooker switches, water heater ones and FCUs are normally DP switched. Recent 13 amp sockets too.
--
*The modem is the message *

Dave Plowman snipped-for-privacy@davenoise.co.uk London SW
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@gowanhill.com wrote:

If it's *that* frequent, a useful first pass might be to unplug everything and see if it still trips (i.e. RCD gone faulty)
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Wednesday, 15 August 2018 15:45:12 UTC+1, Mark wrote:

Could be a loose connection in a plug, I'd look at the oldest devices I have forst see if the cables need tightening or fixing. If it;s regular could be a noiey temp control switch on whatever you have on at the time, normally it might be a fridge/freezer.
Sometimes when I chneg chennles on my TV my dyson fan switches on or chnges speed, hit the same control again and nothing happenes (to the fan anyway) Not narroeed in down to why yet or what exactly causes it. But it;s happend about 5 times this year so far.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Wed, 15 Aug 2018 15:45:03 +0100, Mark wrote:

First thing I'd try to eliminate is anything with a water heating element, kettle, washing machine, dishwasher, immersion heater, etc. Bear in mind unless the device has a double pole switch in the off position, if it's connected a N-E fault can trip an RCD.
After that it would be switching of individual circuits at the consumer unit but bear in mind MCBs are single pole... Maybe a deliberate N-E "fault" is required to see if that can trip the RCD. It doesn't here but thats because the supply has a shared N and E.
At least witha 5-10 minute cycle time it shouldn't take long to find.
--
Cheers
Dave.
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 15/08/18 15:45, Mark wrote:

Favourites are (as others have said) stuff with heating elements, but especially anything that heats water.
Only sensible way is to isolate stuff in turn, but if you have an electric shower, I'd start there.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 15/08/2018 15:45, Mark wrote:

Erm that often is the easy way ;-)
Other suggestions here:
http://wiki.diyfaq.org.uk/index.php/RCD#Nuisance_trips
--
Cheers,

John.
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.