Soldering iron is not hot enough or very reliable


Received our first STEM kit (Spencer) and tools. The USB soldering iron is the weakest thing in the whole kit. It would only heat up 50% of the time and never really got hot enough to solder with (hot enough to burn but it can’t make a good joint).

Luckily I already owned another soldering iron and so was able to complete Spencer, but, you might want to switch to another supplier if you get a lot of reports of this (I can see other posts on this forum saying they have similar issues, but, I don’t know what the failure rate is).


Thank you for supporting our work and for your feedback.

I am sorry to hear that your having issues with your soldering iron.

Please reach out to us via and provide photos of your soldering iron and we’ll send you a replacement if it’s defective.

Thank you

Hi, I’m having issues with my iron too. Working on the Spencer I managed to solder the first pin headers on with no issues, then when I went to solder the resistors on the soldering iron was not hot enough to melt the solder any more. The light comes on fine in the soldering iron but the tip does not heat up. Tried some other irons, checked all the cable connections and still no joy.

Can someone help me troubleshoot / replace it? Bit of a shame it seems to have failed on step 2 :frowning:

Hi Henry,
Thank you for supporting our work and I am sorry that you’re having issues with your soldering iron.
Can you please send us a few photos of the iron via email to

Thank you