I've started using a brand new soldering iron for the first time and it's not working as expected:

  • After about 10 seconds of power, smoke starts coming out from inside the handle, next to the metal shaft. After 30 seconds on, there's a lot of smoke pouring out, like a candle that's just been extinguished. I've turned it off and on and this still happens
  • There's no smoke from the tip, and a very small amount from where the tip attaches to the shaft
  • The tip doesn't get hot enough to melt solder after being on for a little over a minute. I haven't tried leaving it on for longer than that because the amount of smoke from inside the handle seems to just keep increasing. The handle doesn't seem to get noticeably hot in this time

I bought it in a 230V country (UK) and am using it in a 230V country. It's a 40W Maplin soldering kit.

I expected the tip to smoke, but not the inside of the handle. Looking this up online, I see a lot of similar questions being mis-read as being harmless tip smoking, and a lot of comments that they're often coated in oils that burn off. It seems to me that these wouldn't be inside the handle, though? Or would they? Some other comments seem to think this is a sign of a defective iron, but don't offer anything to back up this opinion beyond "I've never seen that".

Just found in the paperwork:

The first time you use the soldering iron, it may smoke slightly and there may be a smell of burning as the heating element dries out. This is normal and should only last a short while

...which sounds unusual and is a little vague. This seems like it'd explain the small amount of smoke where the tip joins the metal shaft, but I'm not sure if this would explain large amounts of smoke from within the handle.

Update: I tried leaving it plugged in outdoors under supervision (fire extinguisher at the ready). After about 7 minutes it seemed to stop smoking, so I took it back inside (keeping the fire extinguisher handy), let it warm up again for a few minutes, started soldering, then noticed it was smoking again. It stopped smoking pretty quickly after killing the power, and was still hot enough that I could finish my soldering, but I think I'll be looking for a replacement.

  • 1
    \$\begingroup\$ This brings a new definition to "fire starter"... \$\endgroup\$ Jul 17, 2016 at 18:48
  • \$\begingroup\$ @IgnacioVazques-Abrams Twisted fire starter! \$\endgroup\$
    – winny
    Jul 17, 2016 at 18:53
  • \$\begingroup\$ Return it to the store and/or local authorities! \$\endgroup\$
    – winny
    Jul 17, 2016 at 18:54
  • \$\begingroup\$ +1 on your safe practice of having your fires outside. Much easier to put out and less risks to start with. \$\endgroup\$
    – winny
    Jul 17, 2016 at 19:37
  • \$\begingroup\$ He can't return it to Maplin as they are under administration. BTW what is the reason of buying overpriced Chinese crap from Maplin. Those 40W "kits" you can buy for 5 quud \$\endgroup\$ Mar 25, 2018 at 23:58

3 Answers 3



I bought one of those from Maplin a year or so ago. It produced a lot of acrid smoke the first time I turned it on, and I was also concerned about it. It's a very cheap and nasty product.

I dismantled it insofar as was practical, but couldn't see anything wrong with the wiring, but there was some residue on the hot parts which was burning off. I put it back together, plugged it into a RCBO protected extension lead, and left it turned on sitting on a fireproof mat in the garden for a while. The smoke died away in a few minutes, and the smell was gone after an hour. The iron has been perfectly serviceable ever since.

Now, I haven't seen your iron, so I can't say for sure whether it's the same. Can you safely leave it somewhere for the smoke to die away? Somewhere fireproof, just in case.


Yes this is a problem. Don't inhale the smoke, and return it.

The tip should not really smoke either, except for when you are putting flux on it (a lot of solder will have flux-cores, so solder will make it smoke some too).

  • \$\begingroup\$ Can you elaborate? What would likely be causing the smoke? Some sources mention it's not uncommon for some irons to have oils on the metal parts that burn off on first use (not sure why they'd be inside the handle though) \$\endgroup\$ Jul 17, 2016 at 19:00
  • \$\begingroup\$ The flux itself kind of burns up. Maybe it's not technically smoke, but it looks like wispy smoke. This should only happen at the tip, where the solder is contacting the iron, when in use. In your case, I have no idea. But there should not be smoke. Probably a bad connection or component that is burning up and heating up the nearby stuff. But I can guarantee you that under no circumstances should smoke continuously pour from the handle of the soldering iron. \$\endgroup\$
    – jbord39
    Jul 17, 2016 at 19:02
  • 2
    \$\begingroup\$ And yeah it could smoke a little the first time. But what you are describing is not that. Go ahead and keep using it if you insist but I sure as hell wouldn't. \$\endgroup\$
    – jbord39
    Jul 17, 2016 at 19:24

It's common for manufactured items to have some trace amount of surface contamination; in particular, metal items may have residues of oil or similar substances. So, a device intended to get hot may smoke a little bit when new until the contamination is burned off.

That said, nothing inside a handle should be getting hot, and even at the tip, there should be no more than a few wisps of smoke.

It sounds like your iron has a poor electrical connection inside the handle, which could be getting hot, even if it isn't noticeable; the smoke would then be coming from burning insulation.

It seems like your iron is defective, should not be used, and should be returned.


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