Relay not switching on schedule

Hi all

I’m trying to setup the relay to turn on a central heating pump when the temperature in the tank reaches a certain value. Water is heated by a wood stove.

I have the unit setup on the network, even publishing to a MQTT server, all looks great.

I set up the schedule for different temperatures and selected the “cooling” rather than “heating”. To test it, I set up different times with temperatures above and below the actual water temperature in the tank. Just to see if the relay switched on and off correctly.

However it seems it doesn’t. When the set point is lower than the actual temperature I would expect it to turn the relay on, but it doesn’t.

So I don’t know what I am doing wrong…

I could control it from nodered presumably but I’d rather have the built in schedule taking care of it.

I’m running Firmware version: 3190

Any idea’s most welcome, it’s driving me mad!

Attached a screenshot of when I would expect the relay to come ON, as it should be cooling??

Hello @Matt-LT it might be worth contacting Martin Harizanov about this About – Martin's corner on the web, he developed this device and is probably best placed to help. Im not that familiar with the schedule functionality Im afraid.

Thanks Trystan, will do!


Two things pop in my head:

  1. Hysteresis is set to a large amount, so it won’t kick in until set point minus low hysteresis is reached. Try with 0 for both hysteresis

  2. The device isn’t getting NTP time and therefore can’t run the schedule procedures. Does the NTP menu give you correct time? Is the time zone and DST offset correctly set?


Hi Martin

Thanks so much for taking the time to reply.

The Hysteresis was set to 0.5C and the difference between setpoint and the actual temperature was greater than that…

NTP was setup and showing the correct time on the schedule page… BUT the GMT offset was zero and I’m in France so should be 1… I’ve changed it and will see what happens!

Thanks again.


Hi All

Well, I think Martin nailed it straight away. I believe it was the GMT offset as it is working now. Also yesterday when it didn’t turn on the relay as expected, I checked later in the same schedule window and it had turned on. So suggesting that it was just an hour behind on the schedule.

I’ll install it today and once it’s been running for a day I’ll confirm.

I hope this helps someone in the future. Thanks for all your help!


1 Like

Hello @Martin_Harizanov

The MQTT Wi-Fi Thermostat/Relay its very useful and robust, although I have a similar problem related to this topic.

I have two relays (Firmware version: 3190) that suddenly stop syncing date and time. Both relays work fine for weeks or months and everything is set correctly. I’ve been using it for years in manual and in schedule modes.

But some days both loose synchronization at the same moment. Time is correct but year says 1970 so Schedule do not work. If I restart the units both sync again and work fine for some time until it happens again. (I had to take cold showers on winter :frowning: )

I thought it was something to do with power outages so I tried to replicate the problem. I cut off the energy of the modem/router and one of the units and then turned both on. The results: the unit that I kept turned on is still synchronized; the unit that was powered off is not (weird, now it has wrong time and year 2106). The router takes long time to restart.

Screenshot 2022-08-28 at 10-13-54 NTP settings
Screenshot 2022-08-28 at 10-13-41 NTP settings

So I have some questions:

  • Why it does not synchronize even when is later connected to Internet? It does not synchronize periodically?
  • Is there a solution for this? For example, can I restart the units daily through Home Assistant?
  • Has the new firmware v3361 Oct 2019 improvements that could solve this issue?

It is crucial for me to solve this so I hope you can help me!