Last Feb my T300si, 10kW developed a fault (I've forgotten what) so I grudgingly forked out about £140 for an engineer visit. He replaced the circuit board in the key pad. I noticed at the time that when he tested the shower he had the heat setting in the '20 to the hour' position which seemed a bit high but I thought nothing of it.
Now we are having to run it at maximum setting since the incoming water is colder. I am worried that when the weather gets really cold (it hasn't happened here yet) the shower won't cope even though it's 10kW. (Our previous one was 8.5 kW and, though the flow rate was not brilliant was acceptable.)
Since, as far as I can tell, temperature depends on flow rate are there any adjustments I can make. I'm going to phone Triton since it is not a year since last February but I bet the 'small print' will defeat me - 2 call-outs = 1 new shower!
Anyone have any suggestions?

Tony Lee, January 2014

In order to come to the correct analysis you would need to test several parts,first thing would be the current it is taking [about 40amps ] if it is correct the stepper motor would need to be checked to see if it is altering the water rate,there are no adjustments that anyone can change

toptrish, January 2014

the shower can only heat so much water so if you have high water pressure/flow rate the temp rise in colder weather is lower.reduce the water flow rate.this gives the shower more time to heat water and therefore you get hotter water to stand under but less of it

A1, January 2014