Domoticz

Hello,

I am looking for a solution to automate my hot water boilers. The boilers are conventional Stiebel Eltron boilers that heat water for the showers and the sinks. For other parts of my smart home I use Sonoffs flashed with espruna firmware and mqtt as protocol. The problem is that I want the boilers to run only during the night because the electricity is 2 times cheaper and I am afraid that some night the boilers might not turn on and neither I nor domoticz would know it.
By specification mqtt has an option for acknowledging messages or in other words when domoticz says to the sonoff “turn on” the sonoff will return a message saying “I am on”.
Can you suggest me a way of doing this, so I can be 100% sure that my boilers will turn on on schedule?

If you for this device purchase a Zwave switch device and a zwave stick, should do the trick as Zwave is providing acknowledge.
I know it's not as cheap as Sonoff, but a few times your wife is angry as she have a cold shower only in the morning, might be worth the extra money

I have fibaro home center 2 as a main system and I use domoticz as secondary controller. I know that z wave has acknowledgement, you can’t even change the state of a switch if its not working. The problem is I do not have Z wave coverage where my boilers are because the walls are concrete and are very thick. So I was looking for an alternative...