What is this part?

[dakaros]

I took apart my steam boiler to clean it and lost a small part that I'm not sure is important.

There is this small cylinder on top of the steam boiler that two wires connect to. It normally has a small red tipped cap that covers the contacts within, but it popped off and I can't find it. Is there somewhere I can find a replacement? Is it necessary to replace if I'm only missing the cap?

Image: https://1drv.ms/i/s!AktH3XVnqXM0h_dJMtUZFx_zZI2iUQ?e=h9M7g0

[chas]

It's a thermal breaker that trips when the boiler gets too hot. Thermal breakers are available from many vendors. However, this one sits on a threaded part that screws down into the top of the boiler and conducts heat up to the breaker. The red tipped cap is part of the reset button. Normally, one of the power leads to boiler connects to one side of this breaker, then a short jumper wire of the same gauge goes from the other breaker contact to one side of the heater element.

Here's one place you can order a replacement though the webpage has the photo upside down: https://clivecoffee.com/products/la-spa ... ety-switch