Replacing ceramic hob

[Merlin5]

Hi guys. After 8 years of good service, my hob is all but dead. Three out of four of the element rings have stopped working, so it's hanging by a thread now. I have just one smaller ring to cook on. I'm going to buy this hob,

https://ao.com/product/e6431c-hisense-ceramic-hob-black-64111-38.aspx

it has a 2 year warranty and is very inexpensive. I've got a Hisense fridge freezer which I've had for 2 years and it's great so I don't mind the brand.

I'm just deciding if I'm able to wire it myself or get AO to do it. I'm not confident with electrics. I've removed the top drawer and unscrewed the 4 screws that hold it in place over the worktop and can see that the thick grey cable is going into the wall behind. So it appears the only way to wire a new hob is where the cable terminates at the black terminal block on the old hob. And apparently the new hob comes without a cable.

Looking at the black terminal block under the hob, there's 4 screws and 3 wires. I'm just wondering if the new hob will wire up exactly the same, and also if the unit would have standardised hole positions, ie, screw down into the same 4 positions where those silver brackets are? Also, the new hob is 6 kW electrical connection and 25 amps fuse rating. My old one is 5.5 to 6.6 kW and the manual says it must be wired into a 30 amp double pole switched spur outlet, whatever that is. Does that mean that my wiring and fuse rating is already good enough to take the new hob?

I'm thinking of just chickening out and paying the £100 to get AO to install it, assuming the installer won't have any issues wiring it with the existing cable and screwing the unit down? It would be free delivery, so £209 doesn't seem bad.




Screw brackets on each side.



From manual

 

[Merlin5]

£100 to fit it????

wtf?

I paid a local sparky £20 cash he even had to cut a bit more out of the worktop.

Its easy enough to wire it BUT... it will be on a much more dangerous circut to run an oven on, if you are not confident dont do it. But seriously mate, ring around £100 is ridiculous.

Do you get on with ceramic hobs? WE dont have piped gas here so so need to go electric, we have an induction hob I'd never go back to any of the other electric alternatives.

EDIT: Thinking about it, he even needed to change a bit in the consumer unit/upgrade one of the circut breakers

You're quite right mate, don't know what I was thinking. I need to get a sparky in, I'm not going to attempt it myself. I'm fine with ceramic hobs. I doubt I'd get a sparky for £20 but even £50 would be ok. Your sparky doesn't happen to be in London does he? I could use him if you think he's alright.

 

[Merlin5]

Double pole just means it switches both live and neutral, biggest issue you have with replacing hob tops is the size of the whole in worktop.
Wiring can be either 3 wires live, neutral and earth or sometimes they can have links to put across lives, sometimes neutrals.

That's why I'd rather get a professional to install it. As far as the worktop, my current hob is 59cm wide by 52cm deep and the one I'm buying is 59.5cm wide by 52cm deep so I assume it should fit fine and I'll lose 0.5cm of worktop space or quarter of a cm each side.

 

[Merlin5]

I know they're really good but I'm not going to buy an induction, I'm quite happy with a ceramic. I'll get an induction in my next home, I might be selling this one soon. There's no point in me replacing the elements, they're £70 to £90 a pop.

The large one on the right at the back went wrong about a year ago. It would glow red, but instead of staying on for about 30 seconds, it would go off about 2 seconds, then a while later come back on and again go off after a couple of seconds, so it never stayed on long enough to heat anything properly anymore.

Then a couple of weeks ago, the small front right stopped altogether, doesn't glow or heat up, completely dead. Then a few days ago, the large front left went the same way as the front right. Last night it started glowing again and stayed on for a good time, then after a couple of minutes it would only glow for a few seconds and then go off too quickly, and then after a few more minutes it didn't glow at all.

I'm guessing it's a thermostat problem in the unit.

 

[Merlin5]

Guys, I've just called a sparky that was recommended to me when I asked in an electrical wholesaler shop. He said he can do it for £60 but it depends if the breaker needs lowering which apparently means replacing. I asked him if I'd blow myself up if I wired it and it was the wrong breaker and he said yes. Do you know anything about breakers?

 

[Merlin5]

I decided I should be ok to fit it myself. I spoke to a sparky that used to do work for my mum. Great guy, knows what he's talking about and has confidence in me that I'll be ok. He said what you both said Budforce and Jez, worst that will happen is trip the fuse but should be like for like wiring. It's coming thursday. If it goes **** up, I'll post a picture of myself looking like one of those cartoons, with my hair sticking up in shock, soot all over my face and a shredded shirt.

 

[Merlin5]

Right then, old one is out and am about to have a go and install the new one. I drew on the photo so I don't get it wrong.

 

[Merlin5]

I'm a bit stuck now. Have I done the jumpers right? I tightened the jumpers down with the screws. But where am I meant to feed the wires through? In the same holes as the jumpers?
I'm guessing I'm correct using the single phase connection?

 

[Merlin5]

Looks like you have the jumpers correct, now just put the wires in.

Green to earth, blue to N1/2 with jumper, brown to L1/2 with jumper.

Ah. So the live and neutral wires go in the same holes as the jumpers. So position jumper in holes, then place wires on top of jumper in same holes, then tighten the screw?


Should I feed the neutral wires into N1 or N2 or an I meant to split the gold wires and feed into both N1 and N2? And same question for L1 or L2.

 

[Merlin5]

Yes that's it, shouldnt need to split the wires the terminal should take them.

Awesome, thanks. I'm hoping the wires will all fit in one hole along with the jumper, because each wire is about a millimetre thick and there's seven of them on the neutral and four on the live.

 

[Merlin5]

After all that, bloody flex cable isn't long enough to reach.

 

[Merlin5]

Yeah, might pop to the local electrical shop but frankly, I don't really want to mess around with flex cable extensions, I'd rather get someone who knows what they're doing.

Does this look dangerous? I just noticed that the earth wire sheath is cut and exposing the wires where it shouldn't, and do the wires at the end look charred?

 

[Merlin5]

They should all have 7 strands. Looks like somebody has cut 3 off the live wire. I would strip it back to 7.

As for earth, they are only sheathed on the end for identification. It runs bare between the live and neutral.

Ah didn't know that. Thanks buddy.

Well here's the latest. I put the hob in place in the hole as it would be used, took the top drawer out, looked underneath and can see that the wires do actually reach fine. However, I can't wire it from underneath, it's just too awkward, dark and difficult.

Problem is, that's the only way I can get the wires to reach. Doing it the normal way on the worktop and across the top of the hole, the cable isn't long enough from there and I can't position the hob close enough to the wires. And I'd risk it falling through the hole or scratching the glass. Fortunately, my mum's electrician called me back and is going to come on saturday to do it for me and said he would only charge £30. I said to him I'd give him a bit more, £40, since I know he's doing me a favour and doesn't need the job. Better than two other sparkys I'd spoken to who wanted to charge me £100 to £120. Meanwhile, I'll continue and see if there's any way I can wire it up but I'm not optimistic.

 

[Merlin5]

It's doable I suppose, might give it another go.
I'm worried about the grey flex trailing across the underside of the hob and sagging.

 

[Merlin5]

Well guys, the electrician came and sorted it for me. He said the cable should have been wired into a box. The guy that installed it in 2012 when I had a new kitchen fitted is a builder not an electrician, so that's why it wasn't done properly. So he's wired the grey flex cable from the wall into a white box, and then put a good length of white heat resistant cable coming out of the box and wired into the hob. There's no problem with the cable getting in the way of the drawers which is good. Everything is working fine.

And now if I ever need to change the appliance, I can easily do it myself as there's enough length of cable to work with wherever the connection box is on the hob.