Steam Iron Repair. Thermal Switch.

The issue that I am going to describe could be a common fault in many steams irons and getting them into a solution just can be a little bit time-consuming... (I agree, we run out of time for this things nowadays!) but It might even be seen as an interesting and non expensive task. 

One day probably happened to one of us that our trustworthy steam iron stops heating up. We might think that after more than 2 years of regular use the heating element could be broken and we should consider it unfixable.

If by coincidence you bumped into the same fault as me, without any doubt I think the fixing chore ritual is gonna be at least much more entertaining with this guide, I can assure you that right now!

 

The above photo shows what we find in our unit after removing a torx screw from the back and proceed to take the cover off the appliance. Here we can get access to another three screws more, one which hold the exposed cables with their connectors and other two screws below which keep top and bottom plastic cases joint together. For sure we will find another two screws (or at least one) on the front part of our steam iron underneath some plastics, we should find them and take them off in order to just keep apart the bottom assembly I show you as it follows:

In the last image we can tell there is a component marked in red, and this is the one faulty thing to blame for. It is a Thermal Switch, also called Clixon. 

Thinking about it could be the case that this fault is caused because of use, specially if there are plenty of temperatures changes that make this little device trigger many many times. Probably It should not break if the temperature would keep itself under control by the main switch (a relay) within a range below the triggering point of the Thermal Switch. 

But in this case as we are talking about an iron of more power than others and with its thermal inertia... seems our steam iron is meant to end up in the recycling or non recycling container after just 2 years of use? we might be able to avoid it!

We will replace our rare  Thermal Switch by an industry standard NC 16A250V 180C, the reason for that? our genuine spare part is a little bit pricey and not at hand.

As you could tell in the following picture there is no much space to refit the unit with this spare part but it can be done under some precautions. The genuine faulty part comes spot welded so we would need to cut it off with some strong wire cutters and we will use the internals of 2 terminal blocks to connect our standard spare part via some faston terminals using some 16A heat resistant wire.

We will secure the replacement part onto the metallic base (where the heating element is) applying some heat resistant and heat conductive adhesive, "Silicone 704" should do the business!

Using a Multimeter we would be able to check that our new clixon works as it should. In this case to make sure It works I jumpered the contact of the main switch (the relay) in order to assure I reached temperatures above 180 ºC for a few moments (this time must not be more than 1 or 2 minutes depending on the Iron), be aware that doing this is not safe because we can be reaching temperatures above 300 ºC.

After unplugging the Iron from mains electricity we will see whether the new clixon works or not, I mean, being above 180ºC the bimetallic strip opens circuit and shuts current, and below 180ºC the connection should be back on again.