UK Gas Cooker conked and electrical cooker replacement

advicewelcom · Nov 5, 2021

Hi, quick posting - welcome any advice as new to this stuff...

Have a Howden HJA 0150 gas grill/oven with a broken thermostat that and can't get a replacement (grill igniting but no gas coming out of oven burners when on).

The Howden grill/oven is on a ring in the kitchen which has following appliances on it:
-microwave
-fridge freezer
-kettle
-toaster
-a Howden gas hob
-the busted Howden grill/oven
-couple of kitchen sockets generally not used

It all goes back to a RCD with a fuse that says - MTN132 b32 hanger fuse

There is an electrical wall connection for the grill/oven, with (I think) a 6mm wire for the ring (and not the thicker 10mm wires used for showers).

I may want to replace with just an electrical gill/oven. So some questions...

-Is there is max kilowatt oven that I could just wire into the current wall socket (which is used for the current grill/oven electrical ignition connection)?

-Would I need to replace the fuse in the RCD for the main? And is so with what?

-Would these things ensure the fuse would not trip if the oven was switched on?

-There are lots of electrical ovens but the instructions say they should be wired directly to the fuse box, so wondering if there is one which can just run from this ring main (if I upgrade the fuse)?

Would hate to buy an electrical oven and then its a nightmare and expense to fit it (the fuse box is currently full).

Welcome advice.

(attached pic of gas connection, and wall sockets for hob and grill/oven)

Avo Mk8 · Dec 6, 2021

advicewelcom said:
So, if the below is correct in the way its wired, you're suggesting plugging the Hotpoint Washer Dryer into the Kitchen Circuit 2 and then the New BEKO electrical oven would be okay on Kitchen Circuit 1?

Yes. If you did that, with every appliance you have running simultaneously flat out, total load would be:
Kitchen circuit 1 (rated at 32A) 31.9A
Kitchen circuit 2 (rated at 20A) 14.7A

Allowing for diversity, no problem.
No fiddling with fixed installation, no additional expense, no tripping.

advicewelcom · Dec 6, 2021

Avo Mk8 said:
Yes. If you did that, with every appliance you have running simultaneously flat out, total load would be:
Kitchen circuit 1 (rated at 32A) 31.9A
Kitchen circuit 2 (rated at 20A) 14.7A
Allowing for diversity, no problem.
No fiddling with fixed installation, no additional expense, no tripping.

Sounds fabulous. Just have to double check I got the right things on the right rings.

But... they have sold out of those ovens at Currys

I assume any 9.7A max oven is going to work?

In Watts, Is the calculation done by:
P (power) = V (volts) x I (current).
W = 240V x 9.7A
W = 2.328kW max oven (with no plug).

Avo Mk8 · Dec 6, 2021

advicewelcom said:
I assume any 9.7A max oven is going to work?

In Watts, Is the calculation done by:
P (power) = V (volts) x I (current).
W = 240V x 9.7A
W = 2.328kW max oven (with no plug).

Yes to both

Every time we discuss an oven, the current goes up a tiny bit!

(only joking)
I wouldn't worry about an extra half an amp.

Ex-display from a reputable supplier might be worth looking at.

Hope you get the matter sorted.

brianmoooore · Dec 7, 2021

The power rating of any appliance sold in the UK should be stated at 230 volts, not 240, which will reduce the current drawn in proportion.
I know electric shower suppliers still con their customers by stating the power output for 240 volts, but I haven't checked if the same applies for cookers.

advicewelcom · Dec 7, 2021

brianmoooore said:
The power rating of any appliance sold in the UK should be stated at 230 volts, not 240, which will reduce the current drawn in proportion.
I know electric shower suppliers still con their customers by stating the power output for 240 volts, but I haven't checked if the same applies for cookers.

W = 2.231kW - 2.328kW max

brianmoooore · Dec 7, 2021

That's at 240V, according to your previous post. A cooker is a resistive load, and this one equates to 24.74 ohms. At 230V, this gives 9.3A or 2139W

advicewelcom · Dec 8, 2021

advicewelcom said:
Kitchen Circuit 1: 32A
ignore A - some kitchen sockets hardly used
ignore A - Gas Hob
7A - microwave
2A - fridge freezer
8.3A - kettle
5A - toaster
7.7A - Hotpoint Washer & Dryer RD 966 J
Total so far = 30A
9.6A - Potential New BEKO oven
Total of all = 39.6A

Kitchen Circuit 2: 20A
3A - Vailant boiler (takes less, but that's the fuse)
3A - Hive (as above)
1A - Couple of plugs hardly used?
Total so far 7-8A?

Oh Gawd...

Just checked and it looks like the twin sockets next to the boiler are on Circuit 1 and the fuse spur on the right for the hob electrics in also on Circuit 1 (pic attached)

So looks like this....

Kitchen Circuit 1: 32A
ignore A - some kitchen sockets hardly used
ignore A - Gas Hob
7A - microwave
2A - fridge freezer
8.3A - kettle
5A - toaster
7.7A - Hotpoint Washer & Dryer RD 966 J
Total so far = 30A
9.6A - Potential New BEKO oven
Total of all = 39.6A

Kitchen Circuit 2: 20A
3A - Vailant boiler (takes less, but that's the fuse)
3A - Hive (as above)
Total so far 6A?

Which means plugging that washing machine into those twin wall sockets will keep it on Circuit 1.

Is there any way to wire a plug or connect into that boiler fused spur for the washing machine? Or culd the twin sockets be easily connected to that boiler fused spur?

Avo Mk8 · Dec 8, 2021

advicewelcom said:
Is there any way to wire a plug or connect into that boiler fused spur for the washing machine? Or culd the twin sockets be easily connected to that boiler fused spur?

You need to establish exactly what circuit that boiler fused spur is on, what cable size, and what breaker.
Are you sure that's not part of circuit 1 just as everything else seems to be ?

advicewelcom · Dec 9, 2021

Avo Mk8 said:
You need to establish exactly what circuit that boiler fused spur is on, what cable size, and what breaker.
Are you sure that's not part of circuit 1 just as everything else seems to be ?

Hi, checked it out and after turning off Circuit 1 the boiler (and Hive) stayed on, everything else was off. Vice Versa. The twin sockets next to the Boiler are on Circuit 1 (so no point plugging washing machine into those twin sockets). Below is accurate...

Kitchen Circuit 1: 32A
ignore A - some kitchen sockets hardly used
ignore A - Gas Hob
7A - microwave
2A - fridge freezer
8.3A - kettle
5A - toaster
7.7A - Hotpoint Washer & Dryer RD 966 J
Total so far = 30A
9.6A - Potential New BEKO oven
Total of all = 39.6A

Kitchen Circuit 2: 20A
3A - Vailant boiler (takes less, but that's the fuse)
3A - Hive (as above)
Total so far 6A?

Attached pics show the fused spur right and left.

Left fused spur is wired to boiler, right fused spur is wired to the gas hob. Twin sockets are on Circuit 1.

Any method to get the twin sockets onto Circuit 2 so can plug washing machine into it?

Avo Mk8 · Dec 9, 2021

advicewelcom said:
Any method to get the twin sockets onto Circuit 2 so can plug washing machine into it?

I'll try again to explain.
it's not possible to say unless you know what size cable runs to the boiler spur, what size breaker it's on, and whether it's part of a ring serving other accessories as well, or is a radial circuit (ie one cable going from consumer unit to that fcu.), and if the latter you need to be sure of the current carrying capacity of the cable, and if it's serving anything else.

If you can answer the following, there might be a chance of deciding if it's practical. Otherwise you'll need an electrician to investigate and advise (which I recommend).

What markings are on the Hager breaker that serves the boiler fcu - in particular what current rating?
If there's a label below the breaker, what does it say (eg 'boiler!', or 'downstairs lights!')
Does anything else in the house go off if you switch off that boiler breaker (needs checking carefully)
Is it a single twin and earth cable that goes into the back of the boiler fcu, or are there two sets of cables?
Is the cable in the back of the boiler fcu the same physical size as the cable in the gas hob fcu (eg 2.5mm T&E)?

I made the suggestion to plug the washing machine into that socket, as a possible way of achieving the installation of the oven, because it avoided you having to interfere with the fixed installation. Now we are back playing with the house wiring, I think you would be better served getting an electrician in to solve the problem. He would see the best way of doing it, rather than us trying to divine it remotely.
However if you can answer the questions above, we might hazard a guess as to whether it could be a straightforward job for that electrician!

advicewelcom · Dec 9, 2021

Avo Mk8 said:
I'll try again to explain.
it's not possible to say unless you know what size cable runs to the boiler spur, what size breaker it's on, and whether it's part of a ring serving other accessories as well, or is a radial circuit (ie one cable going from consumer unit to that fcu.), and if the latter you need to be sure of the current carrying capacity of the cable, and if it's serving anything else.

If you can answer the following, there might be a chance of deciding if it's practical. Otherwise you'll need an electrician to investigate and advise (which I recommend).

What markings are on the Hager breaker that serves the boiler fcu - in particular what current rating?
If there's a label below the breaker, what does it say (eg 'boiler!', or 'downstairs lights!')
Does anything else in the house go off if you switch off that boiler breaker (needs checking carefully)
Is it a single twin and earth cable that goes into the back of the boiler fcu, or are there two sets of cables?
Is the cable in the back of the boiler fcu the same physical size as the cable in the gas hob fcu (eg 2.5mm T&E)?

I made the suggestion to plug the washing machine into that socket, as a possible way of achieving the installation of the oven, because it avoided you having to interfere with the fixed installation. Now we are back playing with the house wiring, I think you would be better served getting an electrician in to solve the problem. He would see the best way of doing it, rather than us trying to divine it remotely.
However if you can answer the questions above, we might hazard a guess as to whether it could be a straightforward job for that electrician!

Avo Mk8 said:
If you can answer the following, there might be a chance of deciding if it's practical. Otherwise you'll need an electrician to investigate and advise (which I recommend).

What markings are on the Hager breaker that serves the boiler fcu - in particular what current rating?
If there's a label below the breaker, what does it say (eg 'boiler!', or 'downstairs lights!')
Does anything else in the house go off if you switch off that boiler breaker (needs checking carefully)
Is it a single twin and earth cable that goes into the back of the boiler fcu, or are there two sets of cables?
Is the cable in the back of the boiler fcu the same physical size as the cable in the gas hob fcu (eg 2.5mm T&E)?

I made the suggestion to plug the washing machine into that socket, as a possible way of achieving the installation of the oven, because it avoided you having to interfere with the fixed installation. Now we are back playing with the house wiring, I think you would be better served getting an electrician in to solve the problem. He would see the best way of doing it, rather than us trying to divine it remotely.

Hi, thanks, will probs get elecy in, but is hard to find anyone and more chance if I can be specify exactly what the job is and some of the homework is done prior to them coming onsite.

Pic attached of the RCD/MCB box...

Diagram Marking 1 - Is for circuit 1 and is hager MTN 132 B32 - 32A
(Label says sockets but covers things in the kitchen already stated)

Diagram Marking 2 - is for circuit 2 and is hager MTN 120 B20 - 20A
(Label says "Boiler and Twin Sockets" - but the twin sockets next to boiler are actually on circuit 1 when tested).

Have hunted around and there aren't any other "twin sockets" for circuit 2 (would be great if there was) - assume for this purpose there isn't or anything else connected (other than the Hive which is powered from boiler)

Right fused spur pic shows approx wiring size and it seems like there is a wire coming from the twin socket side and also from the wall via top of the socket metal back box. Hence the twin sockets are on circuit 1? (follows from the socket testing).

Left fused spur has one wall wire coming in from the top of the socket metal box and one leaving the bottom of the fused spur casing to the boiler. Hive is connected to the boiler.

Would the quick solution be to connect that twin socket to the left fuse spur on circuit 2 and then plug the washing machine into that socket? Or is there an alternative if this isn't poss?

Avo Mk8 · Dec 9, 2021

advicewelcom said:
Hi,Would the quick solution be to connect that twin socket to the left fuse spur on circuit 2 and then plug the washing machine into that socket?

You seem to have a 20A radial with only the boiler on it, so basically "yes" !
As long as the 13A socket is safely taken out of the radial, and the ring is kept properly continuous after (eg Wago's)
Whoever does it needs to be competent!

advicewelcom · Dec 9, 2021

Avo Mk8 said:
You seem to have a 20A radial with only the boiler on it, so basically "yes" !
As long as the 13A socket is safely taken out of the radial, and the ring is kept properly continuous after (eg Wago's)
Whoever does it needs to be competent!

Ok, hopefully I find someone, but if I can't, to take this on, I could...
-Turn both circuits off and test they are off with multimeter
-Pull out the wire connecting the twin sockets into the right fuse spur
-Connect it up to the left fuse spur in the same way
-Close everything up and test
-Plug washing machine into twin sockets
-Fit electrical oven

Not my preference to do myself, but cannot wait for someone to turn up if the oven has to be replaced. There are no gotcha's here or complications?

DPG · Dec 9, 2021

Surely this needs an electrician in. It's very close to step-by-step instructions on reconfiguring a circuit.

Avo Mk8 · Dec 9, 2021

advicewelcom said:
Ok, hopefully I find someone, but if I can't, to take this on, I could...
-Turn both circuits off and test they are off with multimeter
-Pull out the wire connecting the twin sockets into the right fuse spur
-Connect it up to the left fuse spur in the same way
-Close everything up and test
-Plug washing machine into twin sockets
-Fit electrical oven

Not my preference to do myself, but cannot wait for someone to turn up if the oven has to be replaced. There are no gotcha's here or complications?

Just to clarify - I misunderstood how the 13A socket was wired, sorry my error - you’re saying there is just a single cable going from it to the fused spur on the right?
In which case what you describe is a viable way of having it done.