Yes I wll try to change the channels, I use the tmrh20 library and I haven't specify channel for the moment.
Reason:

See here:
http://tmrh20.github.io/RF24Network/classRF24Network.html
#include <RF24.h>
#include <RF24Network.h>
const uint16_t this_node = 031;
void setup()
{
radio.begin();
radio.setDataRate(RF24_250KBPS);
network.begin(this_node);
}
Why ever not? Isn't it as simple as plugging out the nRF24s and plugging them in somewhere else?
Because it's solder on the PCB. ( Domotiser un appareil grâce à un relai V2 - La domotique DIY
