No. Generally speaking there are two methods used. Some Manufacturers use probes inside the boiler which send a signal to the water pump when the level in the boiler falls below a certain level. The other system is a mechanical float inside the boiler.
‘Out of the Box’ both systems achieve the same thing but over time the buildup of scale, from the salts in the water, can have an adverse effect on the probes whereas the mechanical system has the benefit of removing scale as it moves in the water. For this reason all Duplex machines use the mechanical float system for automatic refilling as standard on all models.