Nissan Almera heater not working

It MAY be caused if your new battery is low , due to lack of use , short journeys or alternator not operating properly . It switches to energy saving mode if that is the case and switches off various functions till battery charge is restored .It might be advisable to get your battery and alternator LOAD tested . This is a link describing some of the symptoms

WHEN DOES THE ENERGY SAVING MODE ACTIVATE?
Note that although this mode annoys you a little, it ensures you keep energy in your car. Usually this message is displayed after 30 minutes of using accessories such as the radio with the engine off. However this may depend on the number of accessories activated on your Nissan Almera because it will consume more or less energy and therefore you may get the message instead. Another option, it is also possible that it turns on prematurely when your battery is low.

Then if this message comes on as soon as you switch on your car, this should alert about a battery problem. We advise you to change without delay or to have it checked in a garage. Also feel free to take a look at the article below if you want to get an idea of ​​the price of a battery: Nissan Almera battery change price

To conclude : it is not possible to deactivate the energy saving mode of your Nissan Almera because it is automatic. On the other hand, in the event that the latter lights up frequently, this can signal a battery problem. We advise you to check it without delay because you may get stuck.