how can i fix my electric "triton" shower??

Generally this would indicate blockage / flow restriction of water passing through the unit - possibly a blocked spray head, hose twisted or kinked or inlet filter blocked.

by restricting the flow rate passing over the elements which provide a fixed heat source this will lead to the water temperature becoming very hot in turn causing the Thermal Cut Out to operate causing the water to cool - the cycle will then continue as the temperature then reduces

Triitonman
July 2010