Plug getting really hot? Is it normal?

[uptown47]

Hi all,
I have a summerhouse that has a 3KW heater in it. The other day, the heater was on, and I pulled the plug out to put it into a different socket and I noticed that the plug pins (maybe just the 'live' pin) was really hot (I couldn't touch it because it was too hot).

I've switched the heater to a lower setting (it has a high/low setting as well as the thermostat which I'm presuming controls how much current it draws).

I just wondered if this was normal due to the high wattage of the heater or if it is indicative of a problem somewhere?

Many thanks for your help and advice.

 

[terryplumb]

Check connections in plugs terminals.
A three KW heater would be better hard wired into a dedicated radial circuit.
The socket that it was plugged into would also be suspect.

 

[crystal ball]

Also look at the fuse holder in the plug, some economy brands are a bit less springy than others

 

[winston1]

It is one of the faults of the UK fused plug system. The fuses get really hot at 13 amps. I believe the Post Office (as it was then) downgraded 13 amp plugs to 8 amps for this reason.

 

[uptown47]

Check connections in plugs terminals.
A three KW heater would be better hard wired into a dedicated radial circuit.
The socket that it was plugged into would also be suspect.

Thanks Terry. It would be a big job to rewire this on to it's own radial circuit but I appreciate the advice. Thanks.

Also look at the fuse holder in the plug, some economy brands are a bit less springy than others

I'll check the fuse holder. Thanks for the tip.

It is one of the faults of the UK fused plug system. The fuses get really hot at 13 amps. I believe the Post Office (as it was then) downgraded 13 amp plugs to 8 amps for this reason.

So are you saying that it's normal Winston? Thanks

Does anyone know if there's something I can put between the heater plug and the socket that would act as a safety cut out if it was to get too hot? Does such a device exist? It would just give me some peace of mind as I'm paranoid now when the heater is on that it's busy cooking itself in the plug socket? (Although, the problem does seem to be resolved by putting the heater down to the 'low' setting).

Thanks for all the help so far. Really appreciated

 

[Adam_151]

Slightly warm is normal, too hot to touch is a problem, nomally as said its either fuseholder clips, or poorly crimped connections in a moulded on plug thats to blame. Cut plug off and fit a decent quality one. If socket has been visabily damaged, then replace socket too. It'll only get worse if left, I've had to on occasion restort to an old screwdriver and hammer to separate a melted plug from a socket in order to get to plate screws to replace it....

 

[crystal ball]

During the winter I get a few calls to a factory to replace melted plug & sockets that have 3Kw hearts plugged in to 13 amp sockets

 

[mattylad]

Place I worked at the computers in the offices would regularly go down because the girls all bought 3kw fan heaters in and plugged them into the same circuit as the computers, which got to be too much for the 32 breaker they were all on.

 

[uptown47]

Slightly warm is normal, too hot to touch is a problem, nomally as said its either fuseholder clips, or poorly crimped connections in a moulded on plug thats to blame. Cut plug off and fit a decent quality one. If socket has been visabily damaged, then replace socket too. It'll only get worse if left, I've had to on occasion restort to an old screwdriver and hammer to separate a melted plug from a socket in order to get to plate screws to replace it....

Adam, do you have a plug type that you would recommend? Preferably one that I can get on Amazon.co.uk as we're in lockdown so all the shops are shut.

Thanks for all the advice folks. Much appreciated.

 

[Taylortwocities]

It is one of the faults of the UK fused plug system. The fuses get really hot at 13 amps. I believe the Post Office (as it was then) downgraded 13 amp plugs to 8 amps for this reason.

Is this the same Post Office who imprisoned many of their sub-post office staff because the PO provided them the faulty (Horizon) computer system??

False news. How would putting a smaller fuse in help in any way?
The heater will still be able to pull 13A through the 8A fuse for quite a while. The plug and socket will still heat up to the same extent. Eventually the fuse will pop, so postman pat will just install a 13A fuse. problem not solved!

 

[Adam_151]

If you are going to the effort of ordering a plug especially, then I'd go for one of these https://cpc.farnell.com/mk/pf133blk/rubber-plug-black/dp/PL00466 (also available in white), they seem to be in multipacks or well overpriced on amazon. the likes of CPC and RS are still running. Theres also permaplug which is well made, but to be honest, if you have any plug available, I'd just fit that, and perhaps tweak the fuseholder clips inwards a bit to tighten its grip. Also dont forget that screwfix is still doing click and collect, as are B&Q

 

[ajohn]

If the plug, socket and wiring is of decent quality a 13amp draw will result in it all getting rather warm. Traditionally some higher power uk stuff has been limited to 2.4kw or less so in some respects 3kw is down to foreigners complicated by items being really intended for 220v and in practice getting 240v or very very close to it, or even above. The 13amp fuse is for fault protection so in some ways not a rating.

One problem seems to be space heaters. I have had a Stanley for some time, well made etc and rated at 2.4kw. Also a noisy Chinese one rated at 3kw = 12.5amps. I thought about chucking it and getting another Stanley - they seem to have gone to 3kw - people buy on numbers. My 3kw one's plug just gets a little warm. It might run for 20 o 30min before the thermostat kicks in.

I'd suggest an MK socket and a Masterplug but MK plugs connect to the wire in a different way. Unfortunately that have reduced the amount of brass they use for that so may not be as good as they were but may still be the best. They use a terminal post rather than a hole.

Or Duraplug as Masterplug doesn't seem to be available. Toolstation do a Tough plug that looks pretty good to me. The white version is labelled Axiom

 

[EFLImpudence]

Traditionally some higher power uk stuff has been limited to 2.4kw or less so in some respects

So - lower powered stuff.

3kw is down to foreigners

I don't see how.
3kW @ 240V is 12.5A and British electric fires and immersion heaters etc. were presumably made to fit the 13A fuse and plug which isn't used anywhere else.

complicated by items being really intended for 220v and in practice getting 240v or very very close to it, or even above.

Is that the foreigners' fault or the users'?

The 13amp fuse is for fault protection so in some ways not a rating.

True, but if one cannot use 12.5A appliances on such things without causing damage then something is wrong.


Loose connections.

 

[winston1]

Is this the same Post Office who imprisoned many of their sub-post office staff because the PO provided them the faulty (Horizon) computer system??

As I said the Post Office as it was then. Then they ran the telephone service and it was this section which downgraded 13 amp plugs.

How would putting a smaller fuse in help in any way?
The heater will still be able to pull 13A through the 8A fuse for quite a while. The plug and socket will still heat up to the same extent. Eventually the fuse will pop, so postman pat will just install a 13A fuse. problem not solved!

I never said anything about the fuse. 8amp fuses are not available and in my experience never have been to fit 13a plugs. The PO did not allow personal heaters to be brought in and did not allow 13a plugs to be used with loads greater than 8 amps.

 

[SUNRAY]

As I said the Post Office as it was then. Then they ran the telephone service and it was this section which downgraded 13 amp plugs.



I never said anything about the fuse. 8amp fuses are not available and in my experience never have been to fit 13a plugs. The PO did not allow personal heaters to be brought in and did not allow 13a plugs to be used with loads greater than 8 amps.

Never heard of that for the 22 years I worked for them and we had many a 3KW heater. I should have known as my duties included PAT.

I wonder if you're getting confused with the circuits which originally had 5A sockets on 3/0.029 (<10A rated IIRC) and replaced with 13A sockets. Each had a red sticker afixed giving the maximum current for that socket. I only dumped some recently with 3A stickers, the 3A was the limit of a relay contact rather than the cable size.