Can electric showers' performance be affected by weather?

[Sudu]

Posted here as didn't know if this was an electric or plumbing problem

I have a 7KW electric shower in my flat. Even turned up full the water is only tepid. Could this be because it's having to heat water that is significantly colder because of the recent cold snap?

 

[MANDATE]

correct!

 

[Axel]

Yes, that may well be the case; you may have to turn the flow of the shower down to a trickle to get enough heat into the water, if it's a 7kw. Measure your flow rate, measure temperature of incoming cold, and refer to O level physics book for calorific calculation, to work out temperature rise 7kJ per second will provide...

Someone else on this forum will no doubt post the precise calculation.