On my machine (Miele) the door automatically opens on a hinge for the last 20 minutes of a normal program to let the dishes dry. I have no idea what the eco program does. Afaict it just seems to pauze at random during the cycles, doubling the program time. I never measured the agregate energy use, i doubt much savings can be made on water use as that is extremely low to begin with.
The answer to your (and the headline's) question is:
Eco mode heats up less water, and to a lower temperature and then washes for longer to achieve the same outcome. The heating is the main power draw, compared with the pumping, so it saves energy even though it works for a longer time period.
Exactly. At least from my casual observation, most of the time, the machine does simply nothing. It let's the water soak the dishes, or for the last couple hours, it just lets the dishes dry from the remaining heat (and in the last hour opens the washer so that humidity does not condense again when the machine cools, whereas older machines needed to run a fan to remove it).
Comments
On my machine (Miele) the door automatically opens on a hinge for the last 20 minutes of a normal program to let the dishes dry. I have no idea what the eco program does. Afaict it just seems to pauze at random during the cycles, doubling the program time. I never measured the agregate energy use, i doubt much savings can be made on water use as that is extremely low to begin with.
The answer to your (and the headline's) question is:
Eco mode heats up less water, and to a lower temperature and then washes for longer to achieve the same outcome. The heating is the main power draw, compared with the pumping, so it saves energy even though it works for a longer time period.
Exactly. At least from my casual observation, most of the time, the machine does simply nothing. It let's the water soak the dishes, or for the last couple hours, it just lets the dishes dry from the remaining heat (and in the last hour opens the washer so that humidity does not condense again when the machine cools, whereas older machines needed to run a fan to remove it).
I always assumed they soaked the dishes a bit longer on an eco cycle.
This makes sense to me too. Letting stuff hydrate through soapy water contact or just steam will help de-cake a lot.
And cool “just loaded” porcelain can take a while to warm through, so caked food will release better when warmed up at the contact point.