Ovens and 30A fuse/feed

robopj: 
 If there is an issue with the new oven, it would involve another visit by the supplier (at their cost), and then another visit by the electrician, probably at my cost which I may need to pass onto the supplier.

 

Why would the supplier pickup the costs involved in sorting out your installation if it is considered to be inadequate or installed incorrectly?

Says an electrician who has installed many ovens after the installers booked to do so walked out without doing so.

AJJewsbury: 
 

Am I correct in thinking a kettle wouldn't have a diversity factor applied?

No it still could. The amount of diversity would vary with the situation, 

Agreed

but the main thing about a kettle is that it's only on for a relatively short length of time - a couple of minutes rather hours -

Might seem like pedancy … but it depends where the kettle is installed. In a home, I'd agree with you.

But if it's in a canteen, or a commercial or similar kitchen, and could be on for more than 50 % of the time over an hour, say around lunch time, I would be saying you can't “just ignore” the kettle. If it's on for more than 75 % of the hour, it's like a “full load for the hour”.

 

The installers will install the oven to a correctly installed circuit.

So they will install to a circuit with an accessible local isolation switch and a cooker connection unit behind the oven.

If the switch has a single socket on it then convention is that the load is assumed to be 5-amps when calculating load diversity for a cooker. But you cannot really allow diversity for a single oven, only a double oven or a full blown cooker.

If the oven installation instructions say the oven needs to protected by a 16 or 20 amp circuit protective device then again the installers may walk out without doing the job.

If the cooker circuit has basically been converted to a socket radial circuit then the installers may refuse to just wire the oven to it.

Sparkingchip: 
 

Says an electrician who has installed many ovens after the installers booked to do so walked out without doing so.

Similar here. One customer was refused connection as the 13A socket was behind the adjacent washing machine and the plug on the cooker needed removal to get the cable  through the gap behind the unit.

Apologies, my comments about the installation process have caused lots of feedback.

I wish I knew how to do multiple quotes in my reply to address each point, but I cannot work it out. I'll try to clarify and respond to each post above in this post

Existing connection

I omitted to say that there is a isolation switch for the current double oven. The original standalone cooker switch has been converted to a double socket and a spur used to feed the double oven but there is also an isolation switch on the spur. I missed that point in my earlier posts. I think this would be an “all-pole” or “double pole / double throw" type switch but I cannot tell without removing the faceplate screws and inspecting it.

New double oven connection requirements

These specify an “all-pole” isolation switch.

Comment  about  trying  to  recover  the cost  of  the second  visit  by  electrician

I was considering the scenario where the supplier delivered; electrician attended; existing connection was OK but there was a problem with the double oven - it didn't power up. A replacement oven supplied because the first one would be rejected. The electrician would visit again. I would consider it reasonable to ask for reattendance costs for the second electrician from the supplier. Whether I'd be compensated is another matter. Others may disagree with my thinking. 

We've ordered installation by the supplier, so providing the current electrical connection is OK, I shouldn't need to worry about anything. I tend to worry too much - hence this question :-(

Thank you for all your comments. I think I should be OK with the installation.

Paul

Some reasons for refusal:

• No cooker isolation switch.
• Isolation switch over cooking hob.
• Isolation switch too close to cooking hob.
• Twin and earth directly into appliance without a cooker connection unit.
• Split consumer unit with peak and off-peak in the same enclosure, so the “main switch” doesn’t isolate the entire installation.
• Incorrect protective device.

A couple of times I have suspected it was because of prejudice against the customer or because it was a flat and the  installers had got to carry the appliances up and down stairs.

If you purchase an appliance then you hire an electrician to to connect and you pay for connecting it then OK so far.

If the appliance is faulty then it is the responsibility of the retailer to cover cost of reconnection .

You might offer them the choice or reimbursing you after the event or they provide the reconnection service.

One case I had a couple of years back - A landlord had ordered a replacement oven and asked me to connect it. I attended and opened the box, topside of the chassis had a big dint in it. Actually the cardboard packaging had a big print of two bootmarks on it with wording not to stand on or place weight on it, pre-printed on packaging by the manufacturer. Actual mucky bootmarks on the cardboard almost exactly lined up with the printed ones - priceless. Why the packaging or appliance did not containing a supporting rib against this problem I have no idea.

Anyway the landlord insisted on a replacement and reimbursement for my second visit, paid for by seller. Sometimes you might have to go to court but more often, if need be, getting Trading Standards involved works a treat