Induction hob wiring

Clive_Woody

We currently have an induction hob that is hard wired in with its own 20a MCB, but it had died and I have ordered a replacement. The replacement comes fitted with a 13a plug. Can I simply cut off the plug and hard wire in the new hob or would something need to be done with the mcb?

I appreciate the lower power hob comes with limitations on how many rings I can run on boost, but that's not an issue for me, just wanting to know if this is simply wire in the new hob or is something more complicated required. Thanks 👍

fenwick458

if you cut the plug off and hard wire it in, your warranty will be void. say for example the hob breaks in 1 year and a service engineer visits and theres 2 situations
situation 1, the hob still has it's plug on, still got a 13A fuse in and it's plugged into a 13A socket outlet 
situation 2, plug has been cut off and it's been hard wired

in the first situation, if the hob has developed a fault and is still within the warrantly preiod, the service engineer will fix it or replace it
in the second situation, he will notice the plug has been cut off and just assume that the lack of 13A fuse has caused the problem, without even looking at it, and they won't replace or fix it.

there is no 13A MCB available , so the only option you have (if you want to comply with the manufacturers instructions and have a warranty) is to provide a socket outlet for the hob to plugged in to. this could be added onto the existing 20A circuit if you like, if it's hard wired into a 1G switched fused spur, it's quite a simple job to just change that for a single socket.

Clive_Woody

fenwick458 said:

if you cut the plug off and hard wire it in, your warranty will be void. say for example the hob breaks in 1 year and a service engineer visits and theres 2 situations
situation 1, the hob still has it's plug on, still got a 13A fuse in and it's plugged into a 13A socket outlet 
situation 2, plug has been cut off and it's been hard wired

in the first situation, if the hob has developed a fault and is still within the warrantly preiod, the service engineer will fix it or replace it
in the second situation, he will notice the plug has been cut off and just assume that the lack of 13A fuse has caused the problem, without even looking at it, and they won't replace or fix it.

there is no 13A MCB available , so the only option you have (if you want to comply with the manufacturers instructions and have a warranty) is to provide a socket outlet for the hob to plugged in to. this could be added onto the existing 20A circuit if you like, if it's hard wired into a 1G switched fused spur, it's quite a simple job to just change that for a single socket.

Thanks, I did suspect that removing the plug might invalidate the warranty. There is a junction box beneath the hob (behind a stack of drawers) that the current wire goes into before it goes across into a cupboard housing the MCB. I'm guessing the junction box could possibly be switched for a single socket assuming that there is room behind the drawers?

grumbler

It can be simpler to keep the junction box and to wire a socket to it

Clive_Woody

grumbler said:

It's can be simpler to keep the junction box and to wire a socket to it

Naive question, can you get slimline sockets that would fit in the gap at the back of a drawer unit?

400ixl

If the junction box was purely to enable a 1-2-1 connection with the hob, then swapping it out to a socket would be simpler than adding a socket and then wiring that back into the junction box. I assume the junction box is mounted flush with the wall using a square backplate the same as the socket front plate would use? That way the plug would be the only external part which usually doesn't interfere with the drawers as they don't typically go that far back.

Rodders53

What make and model of hob?

What does the manual say about the plug, fuse / mcb rating (if anything).

Removal of a moulded on plug (only fitted 'cos that's what the regs imply - some appliances still come with rewirable plugs on the cable) should not void any warranty as long as replaced with a suitable (fused, probably) alternative connection.  

(Search these very forums for previous 'discussions' around the same subject for other domestic appliances).  

Clive_Woody

It’s a NEFF T36FB41X0G_BK induction hob. It just arrived and there’s an access panel under the hob that you can flip open and access the connectors for the cable. 

It looks simple enough to undo the screws holding the cable in place and remove the cable with the plug and then use the cable from the previous hob to wire it in to the junction box. 

Does this sound like a bad idea or am I missing something?

Risteard

The simplest options are to either replace the flex outlet with a fused connection unit ("fused spur") with a flex outlet, or probably better still to replace the flex outlet with an unswitched single socket-outlet and simply plug into this. Despite claims made, manufacturers have confirmed that if a competent Electrician cuts the plug top off an appliance and correctly hardwires it in this will not affect your warranty or statutory rights. This is a common misconception. If a non-competent person did it then it may well invalidate warranties.

Clive_Woody

I would not need to cut off the plug as the cable can simply be removed from the hob with the plug still attached and a new piece of cable used to connect the hob to the current junction box, which in turn is connected to a 20a MCB in the cupboard next to the hob. 

I guess my concern is that the hob came with a 13a plug, but if I hard wire it in using the current arrangement it will have the 20a MCB.

Rodders53

Then you need a competent person to read all the hob documentation, it's printed rating plate, inspect / look at the circuit wiring - your suggested alteration and sign it off (or not)...

Neff state:

This hob is equipped with a UK 3 pin plug for an easy plug & play installation. The plug limits the maximum power output to 3.7 KW. For higher power output, please select a hob without plug and ensure installation is carried out by a qualified electrician.

However reading the user manuals it appears the same hob model range has ability to be set to a variety of max load ratings, so it is possible that the almost identical device - without a fitted plug - could be set to suit the 20A supply you have but require a competent person to fit it.