Are the relays controlling AC or DC? If there is nothing plugged into the socket, does the program fail?
What is plugged in to the socket to be switched? Is it inductive or resistive load?
Both relays control 240v AC power line. At the end of the power lines are: small aquarium water pump on one of them and small aquarium air pump on the other. Not sure which type of load that is..
When nothing is plugged in, everything and relays work fine.
If you have AC you may be better off with an SSR and zero crossing switching.
Could you please advise on where to find out more about that, with instructions if possible?
Many thanks!! 