Discuss Need advice regarding electric oven replacement please in the DIY Electrical Forum area at ElectriciansForums.net

Breils

EF Member
Messages
10
Location
Kettering
Hi,

My current oven is a whirlpool 2.3kw hardwired to a 13amp switched spur.

The oven I’m thinking of buying is 13amp and requires a 2.1kw connection.

Can I use the cable from the existing oven and connect it to the new oven?

If so, is it legal to do it myself?

Thanks in advance!
 

Barnaby Stedman

Regular EF Member
Messages
183
Location
England
Yes you can use the same cable as long as it is in good condition. Obviously it would be advisable to check that the cable is on a correctly rated circuit.
 
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Breils

EF Member
Messages
10
Location
Kettering
Thanks for your reply. How do I check that the cable is on a correctly rated circuit? At the consumer unit?
 

Vortigern

Regular EF Member
Messages
4,770
Location
England
It is legal to replace like for like. I imagine your new oven would come with a plug. The temptation maybe to remove the plug and put it in the spur. However that may void the manufacturers guarantee. So you may have to change the FCU to a single socket outlet. There is of course the testing one would need to do. If you have any recent certificates for that circuit you may well be ok. In your case as you can't do testing then you would be on the basis of close your eyes and hope for the best.
 

Barnaby Stedman

Regular EF Member
Messages
183
Location
England
Thanks for your reply. How do I check that the cable is on a correctly rated circuit? At the consumer unit?
yes. at the consumer unit. I expect the circuit would be properly rated but it is worth a check. It would tend to be a 32a ring final circuit or a 40amp radial in 6mm cable.
 
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Breils

EF Member
Messages
10
Location
Kettering
According to the AO website the new oven will not come with a cable.

Can we not assume it’s correctly rated as there is an existing oven?

I have attached photos of the consumer unit and fused switch in cupboard next to oven

B38005C2-BA50-4D15-BE8F-75BCBAF3A5CE.jpeg

00BB90FF-0122-4846-BE95-1FEB00235BF5.jpeg

F60BE407-F943-4C37-AAE3-BA2ABDFCA522.jpeg
 

Barnaby Stedman

Regular EF Member
Messages
183
Location
England
well on the cu it is labelled as cooker socket so i presume it is referring to that fcu you attached a picture of. and that appears to be not correctly rated unless there is another fcu that downrates that fcu - as it appears to be a 2.5mm radial on a 32A breaker - and that is a no-no
 

Barnaby Stedman

Regular EF Member
Messages
183
Location
England
Also the flex running out of the fcu to the cooker might not be the correct rating. if you could find out what size that flex is that would be helpful. it should faintly say on the flex itself.
 

Barnaby Stedman

Regular EF Member
Messages
183
Location
England
Also the flex running out of the fcu to the cooker might not be the correct rating. if you could find out what size that flex is that would be helpful. it should faintly say on the flex itself.
 

Wilko

Electrician's Arms
Messages
5,398
Location
Berkshire
Hi - just going from the picture, the existing flex might be damaged. It might just be a mark but if the insulation is damaged it should be replaced with a new length of 1.5mm.

30389B37-1F51-4743-82E0-6EA73342A863.jpeg
 
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Breils

EF Member
Messages
10
Location
Kettering
We’ve only been in the house 10 months and already suspect that the previous owner was a bit slap dash with the electrics. I was hoping it would be a simple swap given the similar amperage and kw rating of new oven. I think it best to get a professional in just in case what’s already there is insufficient (a c*ck up! ).

Thank you all for your quick replies!
 

Barnaby Stedman

Regular EF Member
Messages
183
Location
England
no problem. your main problems are the size of cables. also i dont think any of the circuits are rcd protected so the sparky will probably recommend you install a rcd
 

pirate

Regular EF Member
Messages
1,936
Location
Glasgow
Don't poke anything into the JB beside the coat hook, or in the hole in the box beside that
 
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Breils

EF Member
Messages
10
Location
Kettering
This is the cooker/hob switch so I assume the oven fcu is a spur off that? The fact that there is a circuit in place and say it’s all correct, can the electrician replace the oven even if there isn’t RCD protection? Or is it a case of no rcd protection no work on any kind of electrics - existing and new?

image.jpg
 

Wilko

Electrician's Arms
Messages
5,398
Location
Berkshire
Hi - you can test if the existing oven is in fact powered from that oven circuit. Just turn on the oven light and then switch off the cooker isolation switch on the splash back.
If there’s no change to fixed wiring the oven may be replaced “like for like” without having to update to RCD etc. Personally, I would think about it though.
 
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Breils

EF Member
Messages
10
Location
Kettering
ok So oven not powered through cooker isolation switch. I turned off the switch labelled kitchen sockets on CU and oven went off. Is that good or bad?
 

Barnaby Stedman

Regular EF Member
Messages
183
Location
England
if the electrician simply wires the new oven in then he doesnt have to install an rcd but I expect you will find he recommends that. to check that that circuit is on a ring main you need to take the cover of the consumer unit and see how many cables run out of that mcb. but that might be a job for your sparky if you dont feel confident doing that.
 

Barnaby Stedman

Regular EF Member
Messages
183
Location
England
ok So oven not powered through cooker isolation switch. I turned off the switch labelled kitchen sockets on CU and oven went off. Is that good or bad?
well its good that the cooker went off but as I have already said I think overall its 'bad' or unsafe because I think it should be on a 20 amp mcb not 32 amp mcb but you would need to check.
 

Wilko

Electrician's Arms
Messages
5,398
Location
Berkshire
ok So oven not powered through cooker isolation switch. I turned off the switch labelled kitchen sockets on CU and oven went off. Is that good or bad?
It is what it is I guess, but it’s not good. Ovens are best placed on the cooker circuit. The kitchen socket circuit likely has a fair bit on it with kettle, toaster, fridge, dishwasher etc. If the cooker connection unit (should be on wall below cooker switch) is near to the oven position it could be connected with a new bit of flex. But I suspect the oven had historically been relocated to this new spot and hence a spur off a kitchen socket for ease.
 
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Breils

EF Member
Messages
10
Location
Kettering
Kitchen sockets 2nd switch in. Yes it is what it is for now. We intend to do an extension and upgrade the electrics then but in the meantime can we remove the cable from back of existing oven and attach to the new oven given it’s the same amperage and 0.2kw less than original?

3E782EB9-6FFA-43CC-A360-D3FE10DFF4C5.jpeg
 

Barnaby Stedman

Regular EF Member
Messages
183
Location
England
Ok. It appears that the kitchen sockets are on a 32amp radial in 4mm - which is just ok. So you can wire in a new oven as long as the flex to the oven is the right size.
 

Barnaby Stedman

Regular EF Member
Messages
183
Location
England
Unless you know the installation method for that cable you cannot predict if it is just okay.
Yes good point there Westward. I suppose I was presuming that that sort of thing had been done by the previous sparky but you never know these days.
Breils - do you have by any chance an EICR for the current installation or not? You would need this to confirm that the cable was correctly protected.
 
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Breils

EF Member
Messages
10
Location
Kettering
Yes good point there Westward. I suppose I was presuming that that sort of thing had been done by the previous sparky but you never know these days.
Breils - do you have by any chance an EICR for the current installation or not? You would need this to confirm that the cable was correctly protected.

Unfortunately, no we have absolutely no paperwork with the house. I guess you just assume everything is hunky dory within reason when buying a house especially when the survey doesn’t flag up anything major, you then move in and within 3 months you’ve had to do a repair to the roof and replace the boiler. But that’s another story. And now our oven takes 30 mins to get to temperature hence why we want to replace but if it’s going to open a can of worms than might not bother for now.

Can you tell the method of installation of the cable by looking at it?
 

westward10

In echoed steps I walk across an empty dream.
Staff member
Moderator
Messages
11,553
Location
Northamptonshire
Can you tell the method of installation of the cable by looking at it?[/QUOTE]
Yes and no. The installation method of a cable can affect its current carrying capacity (ampere rating of cable). Certain installation methods such as containment of the cable in conduit or trunking will result in a reduced current carrying capacity as the cables ability to dissipate heat is reduced. Building materials such as thermal insulation have the same effect if the cable passes through or is surrounded by it. So unless the cable is visible throughout its run it will be difficult to establish.
 
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Breils

EF Member
Messages
10
Location
Kettering
Ok so the oven is on a light grey cable and the extractor fan is dark grey. I removed the plinth from under some cupboards and can see both cables which go through the wall into the understairs cupboard, can see them all the way to foot of stairs where they go under the floorboards and come out in the cupboard where the CU is which is directly across from foot of stairs.
 

tony clark

gaslec instalations
Messages
46
Location
essex
hi i am new to this forum i allso agree with all the above replys
i think you should get it checked by a registered electrician to inspect your installation and tidy up al your lose cables and change your cu with rcd protection
 

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