Water very hot when I switch on immersion heater baxi conden

[alggomas]

I have a baxi condensing gas boiler.

Without the immersion heater switched on the hot water is bearable and does not get very hot.
With , very hot. Why ?
Is it possible to switch off boiler and use immersion heater in Summer?
Switch on only if need shower?

 

[petit_pablo]

Immersion heater thermostat is probably set too high.

It costs ALOT more to heat a hw tank with an immersion compared to a gas boiler.

 

[Agile]

Unless you are someone who lives alone and only takes occasional short showers!

Then it could be no more expensive.

Even so it would still be better and probably cheaper to heat with the boiler just when you want the shower.

Tony

 

[alggomas]

Thanks for both answers.
Will not use immersion heater and check thermostat.