Possible dodgy oven wiring discovered

[Baddegg]

Yes that's right.

In that case it’s on them mate, they can hardly say the oven spec wasn’t discussed if they supplied it, you need to speak to whoever did the works and get an explanation.....do keep us updated we like that ?

 

[Baddegg]

Hi there, not sure how it has been wired. Apparently it is a ring final circuit going by the installation report, not sure if that is a good thing or a bad thing. See attached from the report. In the report it says it is 20A rating.... but there is actually a 32A breaker in the CU. I need to clarify whether that is a typo, some funny business or what. I will ask them to come and clarify what gauge of wire has been used etc, when I try to get them to come back and fix this oven wiring.

The RFC circuit is fine for supplying the kitchen sockets but not an oven that stipulated 16a supply, as a rule anything over 2kw should be on its own circuit, not advocating you doing this obviously but it would be interesting to see cable sizing for that 45a isolator and where it’s fed from....

 

[James2019]

I’ve sent the builder a message and will give him a call tomorrow afternoon. It will be interesting to see what they come back with, will try to keep you updated!

Have I got a couple of different options out of this spot of bother? Losing a bit of sleep here. I attached a screenshot earlier from the EIC, if I understand correctly the kitchen sockets are on a RFC, 2.5mm cable with 32A breaker. In the test results it says 20A breaker, but in reality they’ve put 32A.

I understand that option 1 will be to put in a new radial circuit for the oven. I believe this would involve chasing up the wall, running cable over the ceiling about 10m to the CU. Benefit of a small house... but upstairs would have to lift floor in bathroom, hall and guest bedroom to pull it through and down to the CU.

Is there a less invasive but still above board option 2 available to me? Involving updating some localised wiring from the oven to a cooker switch, while keeping it on this existing kitchen sockets circuit? Or is that a non starter due to the spec of the circuit.

I’m pretty peeved about this, as the house was unoccupied in renovation condition for 5-6 weeks, with floorboards up etc for all the works. The rewire was over £5k excl fixtures and fittings, kitchen fitting £2k etc. And now there is the prospect of getting the carpets up again.

I have visions of me selling this expensive posh oven at a loss and swapping it for a boggo spec <13A oven...

 

[littlespark]

It’s going to be a battle.

First, you have to get the builder to accept responsibility. His electrician, his problem.

Then he will try to convince you to have a sub standard repair job done.... either bodge it off the ring somehow, or run a new radial, but run it in surface trunking.

The least disruptive solution is, as you say, to buy an oven that comes with a 13A plug fitted.... but make sure HE pays for it.

My last post asked if there was an old cooker circuit in the kitchen. Maybe this could be reused? Jointed or rerouted to suit where the oven is

 

[James]

Stick to your guns, the builder employed the spark to design, install and test the electrical installation to supply the kitchen that he installed.
Any issues with communication of specifics or layout is between the builder and spark.

 

[Baddegg]

depending on wether you have a written contract will very much decide the outcome here really, assuming you have then ultimately you could demand the builder install what you’ve paid for and make good afterwards, obviously this will involve living in a building site for a while, without trying to sound condescending there may be cable routes the spark could use that you havnt thought off so may not be as disruptive as you’re imagining, as above have the conversation and stick to your guns ?

 

[Midwest]

No cooker circuit RCBO in the picture. I think someone realised they hadn't got space in the consumer unit that they've fitted, and so they connected the cooker to the socket ring.

Would be interesting to see how the kitchen socket circuit has actually been wired, is it a ring final circuit or a radial and what size cable has been used between the cooker isolator and the sockets?

I might be clutching at straws here, but I'm wondering if a cooker radial has been installed, but just not connected? Did the inclusion of the 'Ring Doorbell' supply, meant there wasn't sufficient space in the CU?

What RCBO isolates the 45A DP Cooker Switch? I suppose the only way to tell from afar, is what cable(s) are behind said switch (and inside CU). Not suggesting you investigate OP.

Have you a pic of the cables entering the CU, on the outside OP (i.e. don't take off CU cover) ?

 

[telectrix]

i'm sure OP is intelligent enough to switch off the main switch, remove the CU cover, and take a pic. obviously observing relevant safety precautions.

 

[brianmoooore]

i'm sure OP is intelligent enough to switch off the main switch, remove the CU cover, and take a pic. obviously observing relevant safety precautions.

A close up pic. of the inside of the CU, showing the brown wires going into the breakers would certainly help.

 

[James2019]

It’s going to be a battle.

First, you have to get the builder to accept responsibility. His electrician, his problem.

Then he will try to convince you to have a sub standard repair job done.... either bodge it off the ring somehow, or run a new radial, but run it in surface trunking.

The least disruptive solution is, as you say, to buy an oven that comes with a 13A plug fitted.... but make sure HE pays for it.

My last post asked if there was an old cooker circuit in the kitchen. Maybe this could be reused? Jointed or rerouted to suit where the oven is

Cheers, thought as much! Oh dear.

Before the re-wire the house had wiring from approx 70s/80s without a dedicated cooker circuit (kitchen shared the downstairs circuit). The previous owners had a gas oven.

 

[Strima]

Looking at the manufacturers instructions the oven should be on it's own dedicated circuit.

The previous owners had a gas oven.

TBH this would be your best option as you already have gas for the hob.

 

[James2019]

This is a picture of the cables entering the CU. The right hand side is where the kitchen breaker is.

I will see if I can turn off the power and remove the cover later, to provide a better view. I’m worried I’ll mess something up.

The builder has responded to ask if they (I believe him and spark) can come tomorrow at 9am to “sort out the problem”. As last night I had said I would like him to arrange for him and spark to attend, resolve the issue and spark to provide a written report explaining how the 16A oven is now wired correctly. I am not sure what they currently have in mind.

 

[James2019]

Here is a photo of the wiring inside the unit. You can see the first post photo for the labels but the far right breaker is the kitchen sockets one.

 

[littlespark]

Just clarify that when the kitchen ring is turned off, the socket that the oven is plugged into goes off. (Ignitor for hob won’t fire)

All you need to say is the oven is too high a rating to be simply plugged into a 13A socket.
The builder and spark can then argue amongst themselves whose fault it is.

Dont take anything else apart, there’s no need to.
Bottom line, they designed it, they supplied the oven. The circuit for the oven should be there.

 

[Strima]

When the spark turns up tell him to leave the half starve rat in his van that he used to trim the cables with.

 

[James2019]

Just clarify that when the kitchen ring is turned off, the socket that the oven is plugged into goes off. (Ignitor for hob won’t fire)

All you need to say is the oven is too high a rating to be simply plugged into a 13A socket.
The builder and spark can then argue amongst themselves whose fault it is.

Dont take anything else apart, there’s no need to.
Bottom line, they designed it, they supplied the oven. The circuit for the oven should be there.

Yes that’s right, when the kitchen ring is turned off all the sockets in the kitchen go off. Including the neon for the cooker switch and the electric ignition for the hob won’t work. If the kitchen ring is on, the neon for the cooker switch illuminates.

I will see what they can suggest for me.

 

[westward10]

If a so called electrician connected that consumer unit I fear the quality of the rest of the installation. I would be wary of them doing anymore works in your property.

 

[Strima]

It is a recommendation in BS7671 (appendix 15 note (iii)) cookers and hobs with a rating exceeding 2kW be connected on their own dedicated radial circuit.

 

[telectrix]

Here is a photo of the wiring inside the unit. You can see the first post photo for the labels but the far right breaker is the kitchen sockets one.

can't believe an "electrician" fitted that abortion. more like a builder using a spade to dress the cables.

it shouldlook more like this:

 

[loz2754]

Not the neatest consumer unit install I've ever seen.
As an aside, I can't see any main bonding cables. Could be that they aren't needed, or connected to a main earthing terminal elsewhere...