Is new cu required for new oven install?

[Jules123]

An electrician has recently quoted to replace our old oven. He says that the new oven has different power requirements and he needs to replace the consumer unit to make this lower and avoid burning out our new oven within weeks! The cu was new in 2015 so I am concerned that it now needs replacing - this will cost double the cost of the oven... Help please!

 

[telectrix]

him talk with forked tongue. if there isno spare waysin the existing CU for the cookwer, then a singleway unit could be instaaled, splittong the feed taitsfrom the metaer/isolator.

 

[newfutile]

I can’t see why it would need lowering and require a new Consumer Unit , the oven will only draw as much current as it requires .ohms law demands this at the same voltage

 

[Spoon]

An electrician has recently quoted to replace our old oven. He says that the new oven has different power requirements and he needs to replace the consumer unit to make this lower and avoid burning out our new oven within weeks! The cu was new in 2015 so I am concerned that it now needs replacing - this will cost double the cost of the oven... Help please!

Welcome to the forum.
I'm not as polite as the others and will say that it sounds like the electrician is talking rubbish.... or you may have misheard them.
Get the electrician to put a his explanations in writing and then post that up on here.

 

[MJPD29]

Worst case scenario a new smaller cu (1 way) can be installed for oven. Can't see any situation where a 2015 board would need changed for the sake of an oven.

 

[Jules123]

I can’t see why it would need lowering and require a new Consumer Unit , the oven will only draw as much current as it requires .ohms law demands this at the same voltage

Thank you. It's just a Hotpoint oven. Can't understand why it would be an issye to wire in. He said something changed 8 years ago...

 

[Jules123]

Welcome to the forum.
I'm not as polite as the others and will say that it sounds like the electrician is talking rubbish.... or you may have misheard them.
Get the electrician to put a his explanations in writing and then post that up on here.

Thanks. It's only a Hotpoint oven. I'll ask about the reason for a new CU.

 

[Jules123]

Worst case scenario a new smaller cu (1 way) can be installed for oven. Can't see any situation where a 2015 board would need changed for the sake of an oven.

Perhaps he only meant part of the board but has quoted around £400 for part and to fit...does that sound right?? Along with other work quoted separately...thanks for your advice

 

[MJPD29]

It really depends on your location as prices vary massively across the country. I wouldn't expect a full board change to be as little as 400 so it could be for a new separate board. Probably best to get a little more detail off him first.

 

[Midwest]

Picture of existing CU, showing 'breakers/mcb's' etc, especially cooker circuit might assist.

 

[Jules123]

Thanks. It's only a Hotpoint oven. I'll ask about the reason for a new CU.

This was his response: you only have 1 rcd so will have to change the board to pass the certificate. He's quoting £650 to do that.

 

[Midwest]

Picture of existing CU, showing 'breakers/mcb's' etc, especially cooker circuit might assist.

And details of new oven.

 

[Jules123]

Welcome to the forum.
I'm not as polite as the others and will say that it sounds like the electrician is talking rubbish.... or you may have misheard them.
Get the electrician to put a his explanations in writing and then post that up on here.

Thank you....this is what he said: you only have 1 rcd so will have to change the board to pass the certificate.

 

[davesparks]

This was his response: you only have 1 rcd so will have to change the board to pass the certificate. He's quoting £650 to do that.

Wow, that is terrible, they should be explaining things a lot better than that if you are going to have any chance of understanding what they are talking about.

Assuming the job is simply disconnecting an old appliance and connecting the new appliance to the existing installation, without any alteration to the fixed wiring, then it is not necessary.
There is no requirement to issue a certificate for simply replacing an appliance either.

 

[Vortigern]

On the scant information you have given it is hard to say the truth of the matter. How many Kilowatts is your new oven and how many kilowatts is your old oven? If you dont know, give us the model number of the ovens. Does your old oven plug in? Does the new one, i.e. does it have a plug on it??? Can you photograph the board he is talking of changing and put it up here? Of course you could always just return the oven and get a lower rated one to match the one you are replacing???

 

[Vortigern]

Anyway, you don't change a board to pass a cerificate. You issue a Minor Electrical Installation Works Certificate (aka MEIWC) as best practice, but as already stated above it is not strictly required so that sounds like a load of bunkum to put it as politely as I can! So if I have this right, £400 to change the cooker, £650 to change the board, total £1050, is that correct??? I really hope not, if it is he needs reporting to trading standards.

 

[Jules123]

On the scant information you have given it is hard to say the truth of the matter. How many Kilowatts is your new oven and how many kilowatts is your old oven? If you dont know, give us the model number of the ovens. Does your old oven plug in? Does the new one, i.e. does it have a plug on it??? Can you photograph the board he is talking of changing and put it up here? Of course you could always just return the oven and get a lower rated one to match the one you are replacing???

Apparently the old oven was higher than the new Hotpoint DKD3 841 IX one. He said something about old being 40 and new only being 20. Both are hard wired but the position isn't changing. He said the new one would burn out due to the difference...images attached.

 

[Jules123]

Anyway, you don't change a board to pass a cerificate. You issue a Minor Electrical Installation Works Certificate (aka MEIWC) as best practice, but as already stated above it is not strictly required so that sounds like a load of bunkum to put it as politely as I can! So if I have this right, £400 to change the cooker, £650 to change the board, total £1050, is that correct??? I really hope not, if it is he needs reporting to trading standards.

It was £650 I think to install the cooker and the board...

 

[MJPD29]

Thank you....this is what he said: you only have 1 rcd so will have to change the board to pass the certificate.

As long as the oven is rcd protected and mcb/cable is suitablt sized then there should be no issue.

 

[timhoward]

Apparently the old oven was higher than the new Hotpoint DKD3 841 IX one. He said something about old being 40 and new only being 20. Both are hard wired but the position isn't changing. He said the new one would burn out due to the difference...images attached.

Don't think your images worked. Copy and paste works well on this forum for images by the way.

As long as the oven is rcd protected and mcb/cable is suitablt sized then there should be no issue.

Even if not RCD protected I'd still change a broken appliance.
New oven is 4.7Kw. A 'standard' 6 sq mm cable and B32 cooker circuit would be fine. Subject to seeing pictures, it sounds like you should find a different electrician.

 

[Spoon]

He said something about old being 40 and new only being 20. Both are hard wired but the position isn't changing. He said the new one would burn out due to the difference...images attached.

So the old cooker is connected to a 40A breaker and the new one only needs a 20A breaker.?? Is this correct?

I'd consider getting another electrician in to quote for the job...
Maybe there is an electrician on the forum that lives near you (High Wycombe) that could give you a quote.

 

[spynage]

An electrician has recently quoted to replace our old oven. He says that the new oven has different power requirements and he needs to replace the consumer unit to make this lower and avoid burning out our new oven within weeks! The cu was new in 2015 so I am concerned that it now needs replacing - this will cost double the cost of the oven... Help please!

BS. The appliance draws power it's not pushed into it! Totally fraudulent to suggest what he is saying. If it's lower power fine just connect up the new oven. BTW. Its worth checking if he is a registered electrician and wether he has a CPS no. Find out and notify his competent persons scheme, NAPIT, NICEIC etc. Let them know what he is up to.

 

[Vortigern]

I am very sorry, but it seems like you are being conned here. Please try another electrician. And the above I echo thoroughly!

 

[Julie.]

An electrician has recently quoted to replace our old oven. He says that the new oven has different power requirements and he needs to replace the consumer unit to make this lower and avoid burning out our new oven within weeks! The cu was new in 2015 so I am concerned that it now needs replacing - this will cost double the cost of the oven... Help please!

He's either lying or totally incompetent!

If the new oven is only 20A than the MAXIMUM it can draw is 20A.

It doesn't matter that the supply is suitable for up to 40A, the oven can only draw up to 20A .

This is pretty basic stuff for an electrician!

So, regulations:
Since the oven is known as a fixed load in electrical terms, the existing 40A supply can remain as is without the need to change it - merely connect the new oven. (Although if I had a suitable smaller MCB closer to 20A I would probably change it - but it isn't mandatory)

However, it may be the case that your existing installation doesn't have RCDs (although given the age it should) in which case it should be upgraded - for more than the oven!)

Do you have a photo of the board?

 

[davesparks]

He said something about old being 40 and new only being 20. Both are hard wired but the position isn't changing. He said the new one would burn out due to the difference.

OK, it sounds like you have an oven circuit which is currently protected by a 40A MCB and the new oven probably requires a 20A supply, this is likely to be specified in the manufacturers instructions.

Connecting the new oven to the existing 40A supply will not cause it to burn out, this is just not possible.
It is possible that the electrician who has told you this simply doesn't understand the basic science of electricity and genuinely believes that what they are saying is true (this is true for a scary number of people trading as electricians these days) or else they are outright trying to scam you.

Whilst technically it is acceptable to connect the new oven to the existing supply as-is there may be advantages to changing the 40A circuit breaker to a 20A one, but this would not require the whole CU (fusebox) to be replaced! It would only require the one circuit breaker to be replaced, even if it is not RCD protected currently then a circuit breaker which incorporates RCD protection, called an RCBO, could be fitted.


However if there is a genuine reason to advise replacing the CU then any decent electrician would explain this properly along with explaining what the improvent would be and why you might need them.

 

[James]

Echoing the sentiment of most posts above, i think we can agree in summary that it is the electrician that needs replacing, not the distribution board.

following the absurd explanation about a 40A supply burning out a 20A oven in weeks, its incredible that we have all survived the change to led "light bulbs" as they generally use about 90% of the power. so an original 6A lighting circuit should be burning out the new lights within minutes!!

 

[Jules123]

Apparently the old oven was higher than the new Hotpoint DKD3 841 IX one. He said something about old being 40 and new only being 20. Both are hard wired but the position isn't changing. He said the new one would burn out due to the difference...images attached.

 

[Jules123]

So the old cooker is connected to a 40A breaker and the new one only needs a 20A breaker.?? Is this correct?

I'd consider getting another electrician in to quote for the job...
Maybe there is an electrician on the forum that lives near you (High Wycombe) that could give you a quote.

Thanks for replies everyone. Looks like we need to keep looking for an electrician! Had two quote so far and need someone for some kitchen electrics as cowboy kitchen fitters had to be let-go. They were damaging the units! Dream kitchen not going so well atm

 

[Jules123]

He's either lying or totally incompetent!

If the new oven is only 20A than the MAXIMUM it can draw is 20A.

It doesn't matter that the supply is suitable for up to 40A, the oven can only draw up to 20A .

This is pretty basic stuff for an electrician!

So, regulations:
Since the oven is known as a fixed load in electrical terms, the existing 40A supply can remain as is without the need to change it - merely connect the new oven. (Although if I had a suitable smaller MCB closer to 20A I would probably change it - but it isn't mandatory)

However, it may be the case that your existing installation doesn't have RCDs (although given the age it should) in which case it should be upgraded - for more than the oven!)

Do you have a photo of the board?

Thanks for replies everyone. Looks like we need to keep looking for an electrician! Had two quote so far and need someone for some kitchen electrics as cowboy kitchen fitters had to be let-go. They were damaging the units! Dream kitchen not going so well atm

He said it only had one rcd??

 

[James]

View attachment 106475

He said it only had one rcd??

I count two RCD's and i have had 3 beers.
what was he drinking???

 

[Jules123]

Don't think your images worked. Copy and paste works well on this forum for images by the way.

Even if not RCD protected I'd still change a broken appliance.
New oven is 4.7Kw. A 'standard' 6 sq mm cable and B32 cooker circuit would be fine. Subject to seeing pictures, it sounds like you should find a different electrician.

 

[brianmoooore]

Could be manufacturer's instructions stating maximum fusing of 20A, but B20 Europa MCBs are readily available and cheap.

 

[davesparks]

View attachment 106475

He said it only had one rcd??

There are 2 RCDs in that unit, they are the two devices labelled as RCCB.

Whilst I tried to give some benefit of the doubt earlier I would say this confirms you have been outright lied to.

I see no reason why that 40A MCB couldn't simply be swapped for a 20A MCB if that is required, those MCB's are current and still available.

There may be some mention of that CU being plastic when these days we are required to fit metal ones, but that would not prevent the work as you have described it from being carried out.

 

[Jules123]

I count two RCD's and i have had 3 beers.
what was he drinking???

I am having the worse time with incompetent traders atm so glad you guys have all taken the time to tell me what's what. Thought it was bizarre that a replacement oven was such a problem!...

 

[Jules123]

There are 2 RCDs in that unit, they are the two devices labelled as RCCB.

Whilst I tried to give some benefit of the doubt earlier I would say this confirms you have been outright lied to.

I see no reason why that 40A MCB couldn't simply be swapped for a 20A MCB if that is required, those MCB's are current and still available.

There may be some mention of that CU being plastic when these days we are required to fit metal ones, but that would not prevent the work as you have described it from

I am having the worse time with incompetent traders atm so glad you guys have all taken the time to tell me what's what. Thought it was bizarre that a replacement oven was such a problem!...

 

[Julie.]

View attachment 106475

He said it only had one rcd??

Nothing wrong with that consumer unit. (ish)

It has two RCDs!

He can't even count.

You could get the 40A MCB changed to a 20A or 25A, they are available if you want.


Now, it is the case that that consumer unit does not meet current standards, but in itself that doesn't mean it has to be changed.

If there is any sign of heat damage and/or a couple of other things, then it should be changed.

But from your photos, there is no evidence that a change is mandatory.

 

[brianmoooore]

The rules have changed since your CU was installed. Yours is plastic, and only steel ones can be fitted in domestic properties now, but the rules aren't retrospective, so as long as individual parts are available for it (which they are) it doesn't need to be changed.

 

[Jules123]

Thanks so much everyone - this has been super helpful!

 

[Jules123]

Nothing wrong with that consumer unit. (ish)

It has two RCDs!

He can't even count.

You could get the 40A MCB changed to a 20A or 25A, they are available if you want.


Now, it is the case that that consumer unit does not meet current standards, but in itself that doesn't mean it has to be changed.

If there is any sign of heat damage and/or a couple of other things, then it should be changed.

But from your photos, there is no evidence that a change is mandatory.

Thanks so much for your time Julie! Super helpful

 

[Vortigern]

Frankly I beleive that he has breached trading standards in that he has suggested you must have something that actually you do not need. This is fraudulent and he could be prosecuted for such fraud.

 

[James]

Frankly I beleive that he has breached trading standards in that he has suggested you must have something that actually you do not need. This is fraudulent and he could be prosecuted for such fraud.

It would be an interesting case,

Although we can install things into what would be considered non compliant distribution boards by todays standards, and in many cases (including this one by the sounds of it) we should be doing so.
it could be argued that we are under no obligation to do any work that fails to comply with the letter of the latest standards.

the issue to me is how it is put to the customer. there is a difference between
I wont do that
and
i can't do that (with the inference that they would be breaking the law to do such)

 

[Vortigern]

Yes it would be. I think he mis-represented the truth with a view to gain a pecuniary advantage. If he would have said it is recommended or best practive etc, to supply SPD AFDD RCBO RCD ad nauseam that is different to presenting a scenario where he can't install the oven if you do not pay for the "necessary" work. It is fraud pure and simple.

 

[Markyd]

So the old cooker is connected to a 40A breaker and the new one only needs a 20A breaker.?? Is this correct?

I'd consider getting another electrician in to quote for the job...
Maybe there is an electrician on the forum that lives near you (High Wycombe) that could give you a quote.

whereabouts in High Wycombe are you

 

[Markyd]

An electrician has recently quoted to replace our old oven. He says that the new oven has different power requirements and he needs to replace the consumer unit to make this lower and avoid burning out our new oven within weeks! The cu was new in 2015 so I am concerned that it now needs replacing - this will cost double the cost of the oven... Help please!

Hi Jules im in wooburn green.. if you want to get in contact

 

[Markyd]

How do i get in contact with the OP or she get hold of me

 

[James]

Click on their name in the conversation and then click start conversation.

 

[Jules123]

Yes it would be. I think he mis-represented the truth with a view to gain a pecuniary advantage. If he would have said it is recommended or best practive etc, to supply SPD AFDD RCBO RCD ad nauseam that is different to presenting a scenario where he can't install the oven if you do not pay for the "necessary" work. It is fraud pure and simple.

Thanks for all your feedback on this. Glad my gut made me check this. So fatigued following cowboy builders cobbling our kitchen together and damaging it in the process that not sure I have the energy (or time now we're doing the rest DIY) to chase him down but agree he is behaving in a fraudulent manner. Makes me wonder whether he's even fully certified. It was a local recommendation!!

 

[Markyd]

A little update...went round to see the job on wednesday morn, Dual RCD board, 40 amp mcb for cooker circuit, 6mm cable and new oven is 5.1Kw, absolutely no reason for a new board or mcb, An extra double socket is required in kitchen so the only thing that needs doing is upgrade Type AC Rcd to a Type A......The so called sparks was trying to pull a fast one and had no clue what he was talking about

 

[DPG]

A little update...went round to see the job on wednesday morn, Dual RCD board, 40 amp mcb for cooker circuit, 6mm cable and new oven is 5.1Kw, absolutely no reason for a new board or mcb, An extra double socket is required in kitchen so the only thing that needs doing is upgrade Type AC Rcd to a Type A......The so called sparks was trying to pull a fast one and had no clue what he was talking about

Nice one!