3 KW fan heater plug `Pins` are Hot when pulled out of socket - What causes this ?

[chris murphy]

"Hello All",


I was visiting an elderly family member when she mentioned that a 3 KW Fan Heater that she uses makes the Plug `Pins` Hot - I was only able to check this by trying out the Heater and feeling the Plug `Pins`.

These were Hot - even when the Heater was run on the 1 KW Setting - Also I tried the Heater in various Sockets - including the 2 on Kitchen Ring - the Pins were Hot when used on ALL Sockets that I tried throughout the Home - which surprised Me.


I believe that the Home was rewired only about 5 Years ago - I mention that only to establish that the Wiring is `New` Twin and Earth - the Consumer Unit was also changed at that time.


I might expect to be able to feel some Heat from the `Pins` after the Heater has been running on 3 KW - ? BUT not to the extent where they are actually `Hot` [?] - and I was surprised to feel that they were also `Hot` when the Heater was set on 1 KW - ?


Some Members will recognise that I am a Heating Engineer - from My previous Posts on the Forum - So I don`t have the Electrical Knowledge to know what could cause this on the Electrical Installation.

I have told my relative to not use the Heater and I am going to take another 3 KW Heater to Her Home to check whether the Plug Pins also get Hot - before I advise that this is checked out by an Electrician.


What could be causing this ? [I hope that it is the Heater ?] - I feel that the Pins get Too Hot for this to be `Normal` ?

I would be grateful if Members can suggest possible causes - I will NOT be trying to rectify this - any Testing or Remedial Work will be carried out by an Electrician - I would just like to know what the cause could be so that I can tell My relative and probably help Her to arrange an Electrician.


Regards,


Chris

 

[Marvo]

Re: 3 KW fan heater plug `Pins` are Hot when pulled out of socket - What causes thi

To be honest I'd just replace the plug. Minor corrosion or tarnishing on the pins or overtightened connections would cause heat to be generated. If the replacement plug doesn't sort out the issue then a little more digging would be required with some test equipment.

Edit; yes, resistance across a connection causes heat but so does minor arcing caused by tarnishing or dirty plug pins.

 

[chris murphy]

Re: 3 KW fan heater plug `Pins` are Hot when pulled out of socket - What causes thi

To be honest I'd just replace the plug. Minor corrosion or tarnishing on the pins or overtightened connections would cause heat to be generated. If the replacement plug doesn't sort out the issue then a little more digging would be required with some test equipment.

Edit; yes, resistance across a connection causes heat but so does minor arcing caused by tarnishing or dirty plug pins.

Hello Marvo",


Thanks for your reply - I will investigate this - ONLY to the point of checking the wiring to the existing Plug - or replacing the Plug if I see any corrosion when I take out the wires - also I will try another Fanned Convector Heater on the Sockets to see if the Pins on that get Hot.

IF I am still not happy that the Plug Pins are getting `Too Hot` [How Hot is Too Hot ?] - especially with the Heater set to 1 KW - I will have to advise that the Electrical System is Tested / checked out by an Electrician.


IF this turns out to be a Fault / Faults on the Electrical Installation [?] - it seems to be on ALL of the Sockets that I tried - some on the Kitchen Ring - others on the Downstairs / Upstairs Rings - I think that the Upstairs and Downstairs are separate Rings from the labeling at the Consumer Unit.



While obviously the Safety of My Relative and Her Home is of paramount importance I am trying to ensure that She does not have to pay perhaps £150.00 [?] for an Electrician to Test the Installation only to state that it is NOT Defective in any way.

She cannot afford to spend Money unless it is absolutely necessary - unfortunately like many Elderly People She is not what could be called `Financially Secure`.


This is why I asked the very Helpful and knowledgeable Members on here for any suggestions - I wanted to obtain Opinions from the Professionals - NOT to just think `All Plugs get Hot on Electric Heaters` !


Thanks again.

Regards,


Chris

 

[ipf]

Re: 3 KW fan heater plug `Pins` are Hot when pulled out of socket - What causes thi

Does the 'heat' occur with other appliances, kettle for example. It seems like a plug/lead problem, other checks could back this up.

 

[Marvo]

Re: 3 KW fan heater plug `Pins` are Hot when pulled out of socket - What causes thi

..... if I see any corrosion when I take out the wires

Corrosion or tarnishing would be visible on the end of the pin that goes into the socket.



I would say anything much above body temperature would indicate a problem and should be remedied. If the plug is getting too hot to comfortably hold in places then the plastic components will degrade rapidly and it shouldn't be used in that condition.

 

[Marvo]

Re: 3 KW fan heater plug `Pins` are Hot when pulled out of socket - What causes thi

Other possibilities are poorly manufactured plugs with incorrect pin dimensions or even a problem with excessive wear of the actual sockets it's being plugged into etc.

 

[spark 68]

Re: 3 KW fan heater plug `Pins` are Hot when pulled out of socket - What causes thi

Well that's the usual sequence of events Marvo,
A poorly fitting or tarnished plug that runs too hot, the contacts in the socket run too hot and lose their spring, which then makes the plug to run even hotter... and so on and so on, thermal runaway.

 

[chris murphy]

Re: 3 KW fan heater plug `Pins` are Hot when pulled out of socket - What causes thi

Does the 'heat' occur with other appliances, kettle for example. It seems like a plug/lead problem, other checks could back this up.

"Hello ipf",

Unfortunately She does not have an Electric Kettle - She uses a Kettle on the Gas Hob - I had thought to check the Sockets with one - She also does not have any other 1 - 2 or 3 KW Appliances / Heaters.

As I mentioned previously I will be taking another 3 KW Heater when I visit again soon and I will check whether the Plug Pins get Hot on that.


Thanks for your reply.


Chris

 

[chris murphy]

Re: 3 KW fan heater plug `Pins` are Hot when pulled out of socket - What causes thi

Other possibilities are poorly manufactured plugs with incorrect pin dimensions or even a problem with excessive wear of the actual sockets it's being plugged into etc.

"Thanks again",

The Pins are actually `Hot` - way past Body Heat - I am sure that they are FAR Too Hot - which is why I asked about this on the Forum.

I will look at the Plug again when I go back - but I definitely did not see any corrosion on the Pins and the Plug seems to Me to be an O.K. Fit - definitely not either Too Loose or Too Tight - But it could easily be the case that the Strands of the Wires are not complete regarding the size of the cores - I will check this.


Chris





Chris

 

[chris murphy]

Re: 3 KW fan heater plug `Pins` are Hot when pulled out of socket - What causes thi

Well that's the usual sequence of events Marvo,
A poorly fitting or tarnished plug that runs too hot, the contacts in the socket run too hot and lose their spring, which then makes the plug to run even hotter... and so on and so on, thermal runaway.

"Hello spark 68",


Thanks for your reply and description of the process that can cause `Heat Up` of the Plug / Plug Pins - I appreciate your interest and the information in your Post.


Regards,


Chris

 

[Richard]

Re: 3 KW fan heater plug `Pins` are Hot when pulled out of socket - What causes thi

Hello Chris,

Although these plugs are rated to 13A, I don't beleive that they are really suiatable for 3KW for extended periods of time. I have seen a couple of these sorts of plugs with badly melted pins/plugs in the past where people have left from on flat out for prolonged periods. Beause their only 'push-in' terminations, I don't think their really capabable of handling large loads for a long time (thats only my opinion).

Personally, I would doubt that there is anything majorly wrong, but possibly advise you client not to have the thermostat set too high. Also, you could change the outlet if you wanted to eliminate worn terminals...?

 

[Guitarist]

Re: 3 KW fan heater plug `Pins` are Hot when pulled out of socket - What causes thi

Chris, it's very unlikely to be a fault with the appliance, and if it gets hot in every socket then it's unlikely to be the installation. As many of us have already said, it will most likely be badly done wiring/loose connection in the plug or tarnished pins causing more resistance. Small cable will run hotter and I have known that contribute to heat transfer into the plug pins.
Anyway, once the new heater arrives you can sleep easy

Btw, to discount the installation take the heater home and try it there.

 

[chris murphy]

Re: 3 KW fan heater plug `Pins` are Hot when pulled out of socket - What causes thi

Hello Chris,

Although these plugs are rated to 13A, I don't beleive that they are really suiatable for 3KW for extended periods of time. I have seen a couple of these sorts of plugs with badly melted pins/plugs in the past where people have left from on flat out for prolonged periods. Beause their only 'push-in' terminations, I don't think their really capabable of handling large loads for a long time (thats only my opinion).

Personally, I would doubt that there is anything majorly wrong, but possibly advise you client not to have the thermostat set too high. Also, you could change the outlet if you wanted to eliminate worn terminals...?

"Hello Richard",

Thanks for your reply - I am fairly sure that the `Fit` of the Plug Pins is not Too Tight or Too Loose - I had thought about this possibility when I was trying the Heater in various Sockets around the Home - all of the [5 Year old] Sockets seemed to be O.K. regarding the `Plugging in` fit.

Although the Heater is fairly Old it was usually left plugged into the same Socket - since the Home was rewired about 5 Years ago - and before that it was left plugged into the previous Socket Outlet in the same room.

I might not have been too concerned if the Plug was `Warm` when the Heater was set on the 3 KW output - But it was definitely Too Hot - and also Too Hot when the Heater was set on 1 KW.


I am sure that when I investigate the Plug terminations that I will probably find that some of the strands of copper in one or more of the cores are missing - I could not see from just taking the Plug apart as I did not have a terminal screwdriver - I was visiting a Family member when She mentioned this problem to Me.

Whatever happens I will be explaining the options available on a New Dimplex Fanned Convector Heater - Thermostatic Control [which actually turns Off the Heater] and a Timer option which might be helpful for Autumn Mornings - and I will help to obtain a New Heater for Her.


Thanks again for your message - I appreciate your interest.

Regards,


Chris

 

[chris murphy]

Re: 3 KW fan heater plug `Pins` are Hot when pulled out of socket - What causes thi

Chris, it's very unlikely to be a fault with the appliance, and if it gets hot in every socket then it's unlikely to be the installation. As many of us have already said, it will most likely be badly done wiring/loose connection in the plug or tarnished pins causing more resistance. Small cable will run hotter and I have known that contribute to heat transfer into the plug pins.
Anyway, once the new heater arrives you can sleep easy

Btw, to discount the installation take the heater home and try it there.

"Hello Guitarist",


Thanks for your latest reply - the reason that I mentioned the Plug getting Hot in all of the Sockets on different Rings was to possibly eliminate the probability of a `Faulty Circuit` [please excuse the terminology] - I tried various outlets around the Home because I felt that would definitely be appropriate when asking about this on the Forum.

I know that doing this did NOT necessarily mean that there was NOT a problem with the Electrical Installation - but I would have expected that the first thing I would have been asked on here is `Does the Plug heat up in other Sockets - including those on another Ring` - ?

I will check out the Plug wiring - and probably take the Heater Home to try it - IF I can persuade My relative to dispose of it - I could not take it Home when I visited Her as I was going to the Pub afterwards and I was not Driving.

Whatever happens I will try to Insist that She buys a New Fanned Convector Heater - for both Safety purposes and the fact that it would be more Controllable - Thermostatically and a Timed Option.


Thanks very much for your help and suggestions / information.

Regards,

Chris

 

[chris murphy]

Re: 3 KW fan heater plug `Pins` are Hot when pulled out of socket - What causes thi

"Hello All",

I have been back to My elderly relatives Home and looked at the Plug on the Electric Fan Heater - as the Members on here advised Me would probably be the case the Live and Neutral wires had strands missing / cut off when the Plug was being wired - probably at least a Third of the strands on each wire were not connected in the terminals !

I rewired the Plug - as expected when I then ran the Fan Heater on 3 KW the Plug Pins did NOT get `Too Hot` - although as also expected / mentioned by Members there was some `Warmth` at the Plug Top and the Pins.


As Her Heater is very Old [20 + Years at least] I have convinced My relative to purchase a New Dimplex 3KW [plus 1 KW & 2 KW Settings] Fanned Convector Heater.

I saw one of these working during the Winter and it Heated up the Room in a surprisingly short period of time - So as it has a Thermostatic Control [Not just the Temperature Setting] and a Timer facility it will be much better than the Temperature Setting only of Her Old Fanned Heater.


Thank You very much to the Members who helped Me with this - I really appreciate your time and the information that You all posted for Me.

Although there was one Member who obviously thought that I was an `Idiot` and questioned whether I was an `Engineer` [Heating Engineer] - after I had almost apologetically explained why I would NOT have known that Plugs on 3 KW Electric Heaters could get Very HOT.

I had stated that as a Heating Engineer I had never have been in the situation of coming across this Faulty Plug Wiring before - regarding this producing VERY Hot Plug Pins.

Thanks very much to the very helpful Members who did NOT treat Me like an Idiot - but who helped Me to solve this possibly Dangerous problem - those Members did NOT feel that answering My [Very simple to them] question was `Beneath them`.

I have to state that My next visit would have been to look at the Plug Wiring - even without having asked about this on the Forum - So I would have found the situation with the missing / cut off strands.


BUT - I was TOLD what the problem was likely to be by the Professionals on here which I was very grateful for.


Regards,


Chris - [Heating Engineer]

 

[Guitarist]

Re: 3 KW fan heater plug `Pins` are Hot when pulled out of socket - What causes thi

Glad you got it sorted Chris.