Potential boiler issue

[JP0704]

Calling all electrical professionals / boiler tradesmen -WE NEED YOUR HELP!

Every so often (twice in the last two days) when running the hot water in the kitchen it trips our electrics (downstairs lights, sockets, cooker and boiler) and cannot be reset for a good 20-30 mins. This only happens randomly and when running the hot water. We have unplugged all appliances except cooker and it still happened. We have had an electrician out who said all is good (EICR done in July 2023 and all good) and had plumber out to service boiler and also run through cycles of high fire and low fire with no issues (this was completed during the daytime,
Not evening).
We have had the water pressure sensor changed but no change to trips.
When having a shower in the evening it has not tripped the electrics, it only seems to be when using the kitchen hot water.
Any advice greatly appreciated.
Thanks
Jon

 

[littlespark]

There will be certain things like valves and pumps that only switch in when the boiler is running…. A general insulation resistance test with power off may not find these problems.

Is the upstairs and downstairs on separate hot water pipes… maybe one is through a motorised valve?
The valves can be manually held open with power off for IR testing.

If it’s only happening sometimes and not always… it could be difficult to find a fault.

 

[JP0704]

Sorry for the not helpful reply but I am not sure how I would find out if downstairs is on different pipes to upstairs.
Would changing of the boiler / electrical board solve the issue or is it likely to be an individual motorised valve?

What/who would you recommend I ask to try solve the riddle?
It sounds like an expensive fault to find…

 

[James]

I would be looking carefully for any water leaks near the kitchen sink.

 

[JP0704]

I would be looking carefully for any water leaks near the kitchen sink.

Hi James.
Thanks for your reply. We recently had the condensate pipe from the boiler replaced as it was leaking into the cupboard below the sink. There is a socket under there which connects the dishwasher but doesn’t explain why the trips are so random?

 

[Avo Mk8]

Hi James.
Thanks for your reply. We recently had the condensate pipe from the boiler replaced as it was leaking into the cupboard below the sink. There is a socket under there which connects the dishwasher but doesn’t explain why the trips are so random?

Is there any evidence of a leak from the kitchen waste pipe under the sink, eg joints, trap or appliance waste connections, or a leak from around the sink etc? Can you turn off power to the socket under the sink at the consumer unit, and if so does that make any difference (eg if you leave it off 'permanently'?)

 

[JP0704]

Is there any evidence of a leak from the kitchen waste pipe under the sink, eg joints, trap or appliance waste connections, or a leak from around the sink etc? Can you turn off power to the socket under the sink at the consumer unit, and if so does that make any difference (eg if you leave it off 'permanently'?)

Hi. Thanks for the reply. No evidence in terms of water dripping / wet to the touch or signs of a leak on any other pipes.
I don’t believe that can be isolated separately but can check.
The plumber we had round for a separate issue said could be the PCB board?

 

[davesparks]

So the fault only occurs when the kitchen hot tap is used, the fault doesn't occur when other hot taps are used, the fault clears itself after 20/30 minutes?

It could be that the hot pipe to the kitchen tap is very close to a damaged cable or other part of the electrical installation and when it gets hot the expansion puts pressure on it causing the tripping.

 

[davesparks]

The plumber we had round for a separate issue said could be the PCB board?

If it was a problem with the boiler you would expect it to happen with all hot water taps, not just the kitchen.

If the fault only occurs when the kitchen tap is used then the cause is most likely to be something which is unique to the kitchen tap.
The boiler and it's associated systems are going to be common to all of the hot water outlets.

 

[JP0704]

If it was a problem with the boiler you would expect it to happen with all hot water taps, not just the kitchen.

If the fault only occurs when the kitchen tap is used then the cause is most likely to be something which is unique to the kitchen tap.
The boiler and it's associated systems are going to be common to all of the hot water outlets.

Thanks Dave.
Yes it has only been related to the kitchen tap thus far and only has ever tripped in the evening time when washing up dinner plates. Has not happened during the day when using the kitchen tap (as mentioned above the boiler has been checked twice running through various cycles- high / low fire etc and didn’t trip)
So question is should we seek to find an electrician or a plumber to look at it?

 

[JP0704]

Thanks Dave.
Yes it has only been related to the kitchen tap thus far and only has ever tripped in the evening time when washing up dinner plates. Has not happened during the day when using the kitchen tap (as mentioned above the boiler has been checked twice running through various cycles- high / low fire etc and didn’t trip)
So question is should we seek to find an electrician or a plumber to look at it?

Forgot to add here that the heating is on during the time this has happened

 

[timhoward]

I think it would help if you posted a picture of your consumer unit and indicate which device on it trips.
We might then be able to suggest some diagnostic steps to narrow the problem down, and the steps vary depending on the consumer unit design.
And this is very much one for an electrician not a plumber at this point.

 

[JP0704]

I think it would help if you posted a picture of your consumer unit and indicate which device on it trips.
We might then be able to suggest some diagnostic steps to narrow the problem down, and the steps vary depending on the consumer unit design.
And this is very much one for an electrician not a plumber at this point.

Hi Tim
Many thanks for your reply.
See attached. It is only ever that one that trips and it covers downstairs lights, sockets, cooker and boiler.

 

[davesparks]

So question is should we seek to find an electrician or a plumber to look at it?

For an electrical fault you would be better off calling an electrician.

 

[timhoward]

Hi Tim
Many thanks for your reply.
See attached. It is only ever that one that trips and it covers downstairs lights, sockets, cooker and boiler.

Ok, you need a decent electrician. One that understands what his tests are doing.

It's possible for them to take a measurement, run the tap, take another measurement, and determine which circuit is affecting the measurement. Then by further testing that circuit they can home in on the problem.
If it takes 15-20 minutes to reset each time, it's not going to be too bad to find, as it's a reproducible fault.

 

[JP0704]

For an electrical fault you would be better off calling an electrician.

Thanks Dave. Just to note I have had an electrician out who says nothing is wrong, call a plumber who comes out and says it is electrical.

I think the below comment is correct in that I need to find a DECENT electrician!

 

[JP0704]

Hi all. So the saga continues. We have had a new electrical company out. Fitted a brand new fuse board and yet the electrical
Sockets continue to trip. We have nailed it down to just the kitchen sockets but tripped again tonight. They said they split the circuit but they didn’t.
Only appliance on was fridge.
Was running hot water again and it tripped at some point.
Any ideas?

 

[James]

do you have a picture of the new fuse board?

 

[JP0704]

do you have a picture of the new fuse board?

 

[JP0704]

do you have a picture of the new fuse board?

It is no12 that trips. Used to
Be no4

 

[James]

It is good news that you have an all RCBO board, that should help the electrician narrow down the fault.

 

[DefyG]

Circuits 4 and 12 both labelled 'Kitchen Sockets' on 16A MCB's so does look like the circuit has been split with the fault on circuit 12 side.

 

[JP0704]

Circuits 4 and 12 both labelled 'Kitchen Sockets' on 16A MCB's so does look like the circuit has been split with the fault on circuit 12 side.

Yes but I intentially tripped no4 and it didn’t kill any kitchen sockets?

 

[JP0704]

It is good news that you have an all RCBO board, that should help the electrician narrow down the fault.

Yes to the kitchen sockets. No further as of yet.
You know any decent fault Finding electricians in Cambridgeshire area

 

[Bluetit]

Never know, if you let Artisan electrics do it on YT you might get it for free

Edit: It should be getting a fair bit simpler to solve at this point though, limited to a number of sockets, and therefore cables.

 

[JP0704]

Yes to the kitchen sockets. No further as of yet.
You know any decent fault Finding electricians in Cambridgeshire area

Never know, if you let Artisan electrics do it on YT you might get it for free

Edit: It should be getting a fair bit simpler to solve at this point though, limited to a number of sockets, and therefore cables.

We did initially think of them for our EICR but they were EXPENSIVE!
Always tempted by a freebie but not sure about my house featuring on YT if I’m honest.

 

[DefyG]

Yes but I intentially tripped no4 and it didn’t kill any kitchen sockets?

So the whole kitchen (sockets) is on a 16A radial circuit?

Can you tell if the cables and pipework come into contact with one another at some point?

Hot water is just pressurised or gravity? No pump or heater involved?

Perhaps unplug every appliance on that circuit and see if it still trips but I'm sure the other sparks have tried that.

Being an intermittent fault it will be or can be difficult to locate.

 

[DefyG]

What insulation resistance does the certificate show for that circuit(12)

 

[JP0704]

What insulation resistance does the certificate show for that circuit(12)

It was only put in yesterday. Not when they installed the board.

 

[JP0704]

So the whole kitchen (sockets) is on a 16A radial circuit?

Can you tell if the cables and pipework come into contact with one another at some point?

Hot water is just pressurised or gravity? No pump or heater involved?

Perhaps unplug every appliance on that circuit and see if it still trips but I'm sure the other sparks have tried that.

Being an intermittent fault it will be or can be difficult to locate.

I believe yes. I think they downgraded it from 32amp?

The hot water is from a combi boiler.
Can’t see any issues to the eye with wires etc.

 

[Bluetit]

The electrician needs to come in the evening when you are able to recreate the fault. Assuming it is consistent in the evenings with the kitchen hot water on. It should be fairly easy to narrow down the item/leg of the radial causing the issue with an mft if the fault remains for 20mins or so at a time.

 

[DefyG]

It was only put in yesterday. Not when they installed the board.

What was only just been put in, the mcb if not the board? When was the new board installed? and you dont have a test certificate yet?

Seems naive of you and the electrician to think a new board would solve the tripping fault.
Being on a separate RCBO will help minimise the inconvenience though and help locate it but you had already established it was the kitchen socket circuit.?

 

[JP0704]

What was only just been put in, the mcb if not the board? When was the new board installed? and you dont have a test certificate yet?

Seems naive of you and the electrician to think a new board would solve the tripping fault.
Being on a separate RCBO will help minimise the inconvenience though and help locate it but you had already established it was the kitchen socket circuit.?

The RCB was only just put in.
The board was last week and yes we have the cert already.

The new board was not only because of the tripping but because the other was very old.
We couldn’t narrow it down before as it tripped the whole bank.