Boiler / RCD Issue

[parin]

Long time reader, first time poster..

I have been having some issues with my RCD circuit / boiler.

I have a Worcester 24i Junior Combi Boiler installed and when I have it set to 3 on the boiler there are no issues, but when I change it to anything above it trips the RCD.

I called an electrician to test the circuit for any earth leakages but his testing equipment showed everything is ok, he also tested the RCD and there were no issues.

I called the plumber who installed the boiler who could not find any issues.

I called Worcester who replaced the fan, the pump and various other components and it is still occurring. The final time the RCD tripped when the engineer was here, it would not come back on so he removed the fuse from the fuse spur but the RCD would not reset. It only reset when I unplugged all of the the appliances in the flat.

Because of this the engineer seems to think there is a wiring issue, but I'm unsure what to do because the electrician said everything was ok.

Has any one had experience of this in the past, or if can anyone offer any advice it would be most appreciated.

Thanks.

 

[Spark123]

It sounds like a faulty appliance, given that the RCD wouldn't reset until the appliances were unplugged and the electrician has already checked the circuit.
Which appliance did you unplug last to enable the RCD to be reset, or did you just unplug the lot?

 

[parin]

I unplugged every appliance and then turned the boiler on and it tripped again.

This time the RCD would not reset until I switched the fuse spur on the boiler off, once it turned back on I turned the power on to the boiler (did not turn the heating on) and it RCD tripped again. I waited 5 minutes and tried again and it was ok.

 

[swampy2]

Is there any issues with moving boiler onto non rcd circuit ?, is boiler on its own circuit ? . Get sparky to test for earth leakage current before and after boiler fired up ,with a leakage clamp meter . Also for finding leakage from any appliances.

 

[parin]

Is there any issues with moving boiler onto non rcd circuit ?, is boiler on its own circuit ? . Get sparky to test for earth leakage current before and after boiler fired up ,with a leakage clamp meter . Also for finding leakage from any appliances.

The boiler is currently on the same circuit as all of the other sockets.

The only issue with moving it to a non rcd circuit would be the disruption to the walls to chase in the wiring.

I will ask them to do the tests as you said above.

 

[EFLImpudence]

No, just as a temporary test via an extension lead to another socket.

If you have no RCD unprotected circuits, use a socket on another RCD and if that one trips then it is definitely the boiler at fault.

If it works without tripping then you have a fault on the original RCD side.

 

[parin]

No, just as a temporary test via an extension lead to another socket.

If you have no RCD unprotected circuits, use a socket on another RCD and if that one trips then it is definitely the boiler at fault.

If it works without tripping then you have a fault on the original RCD side.

I only have one RCD circuit, the only unprotected circuits is the cooker and electric shower, I will ask the electrician to check it on that.

But if the boiler is tested on an unprotected circuit what would trip if there is an issue with it?

 

[EFLImpudence]

I only have one RCD circuit, the only unprotected circuits is the cooker

If you have a socket on the cooker switch that would do.
Put a 3A fuse in the extension lead.

But if the boiler is tested on an unprotected circuit what would trip if there is an issue with it?

That depends on the fault. Probably nothing.

 

[parin]

I only have one RCD circuit, the only unprotected circuits is the cooker

If you have a socket on the cooker switch that would do.
Put a 3A fuse in the extension lead.

But if the boiler is tested on an unprotected circuit what would trip if there is an issue with it?

That depends on the fault. Probably nothing.

I do not have a socket on the cooker circuit, I will ask the electrician to put one on to test

 

[knowall]

Hi, can you clarify if the Electrician checked the whole installation ?

It sounds like an earth/neutral fault.

Regards,

KA

 

[aesmith]

I only have one RCD circuit, the only unprotected circuits is the cooker and electric shower, I will ask the electrician to check it on that.

Are you sure - normally a shower would be RCD protected.

 

[parin]

I only have one RCD circuit, the only unprotected circuits is the cooker and electric shower, I will ask the electrician to check it on that.

Are you sure - normally a shower would be RCD protected.

Sorry I meant there is one RCd switch, this has 3 circuits. The sockets, cooker and shower.

I put the boiler on the cooker circuit and used an extension lead to supply the boiler and it had the same result. I also isolated all other circuits on the rcd whilst I tested it.

the circuit would also not reset until I unplugged the boiler.

I've called Worcester again and they are coming out on Wednesday.

Fingers crossed.

Thanks everyone for your help so far

 

[EFLImpudence]

Well, it would as you have now said the cooker is also on the same RCD.

 

[parin]

Well, it would as you have now said the cooker is also on the same RCD.

So would I need to put a separate rcd circuit in, with nothing else apart from the boiler to rule out there being a problem with the electrics?

 

[EFLImpudence]

You could do that.

The boiler needs to be on a circuit which is NOT protected by the RCD which is tripping.
Then, if this RCD still trips when the boiler is used the fault must be on the circuits.
If not then it must be the boiler.