For sale is a brand new Thermal Cut-off or Thermostat for the SpaNet Range of heaters. 

This one in particular definitely matches the XS-RH3000 model. Other models check the thermostat model is the same. 

If unsure please send me a message. 

It has a 55 degree cut-off temperature and is normally closed under that temperature. 

It has a switching current of 40A which could switch up to 9.2KW element. It is well over-engineered for the 3KW heater. 

Common failures for these heaters is that the thermostat gets corrosion inside and stops it from switching properly. If the element is fine, this part could save your $700 heater from being thrown in the bin. 

As always these parts need to be fitted by an electrician. 

Please be aware the pictures look slightly different to the actual product. The actual product will be 40A with 55C cutoff. It will have the tabs going straight out horizontally. There are some photos of the damage these can sustain from corrosion. Rest assured you will be receiving a brand new product.