I have a new 8.5kW mains fed electric shower (Triton T80z) which is cold in the morning but warm in the evening.
It has a low pressure indicator light on it so I know it's not a pressure problem (unless the light is broken…).
Anyone have any ideas on how to remediate this?
EDIT:
Thanks DDS, some great info and options there. In the morning it doesn't heat the water at all so it comes out at mains temperature. I've fiddled with the settings (both elements on, max temp set etc) but with no difference made.. any ideas on why it'd do that?
Best Answer
How cold? (20°C, 30°C) Remember that in winter mains water is colder (5°C vs summer's 15°C) and at night it gets even colder: 2° On average, and with a 8,5 kW you can rise only 3,5L/min at 35°C delta (which is really low flow). It means a 37°C shower in morning and 40°C in evening.
I think its a too low power appliance: consider switching to instant-gas that allows by-far better performances. Even going for a 10 or 12 kw electric shower won't improve much your situation. Remember: a flow of 1L/Min (starting at 5°C) requires a power of 2,4 kW. And a good shower (at least in my Italian terms) is 10L/min, although 6L/min is still acceptable.
Another electric option is to install a Point-Of-Use immersion that can give you really better performances (for 2-people shower 40L is enough), at least in winter.