My Triton T90 shower keep going either too hot or freezing cold?

Sounds like your boiler is gone. They can be bought from the main dealers in Maynooth. Funny enough I find this happens in December for some reason (here in Tipp). It happens to me because I get a build up of lime on the inside of the boiler and if it is not cleaned out it will eventually burn out one or both of the heating elements. The 'new' boilers are a sealed unit so you cannot take them apart and remove the lime so now I have the change the boiler every year and it costs about 90 euro. You should get an electrician to change the boiler as there are lots of wires in there. I took a photograph of mine and used it as a reference and did the job myself. Make sure the rubber rings on the inlet and outlet of the boiler are in place when you re-assemble the new boiler or you will get a bad leak.
Regards.
Tom.

tom Burnell
January 2010