The Efficient Home Forum

Hi,
I have just installed Evohome system with HR91 thermostats.
I have 9 zones.Everyhing seems to work OK except one zone.

I have a problem with one zone which has 2 radiators.
I  noticed the temperature in this zone was much higher than I had set on the schedule.
On looking on the display unit I noticed the target temperature was 35 C!

I did not set an override of 35 C.

This has occurred  a couple of times and the target temperature of 35C appears randomly even after I have cancelled it.
I have version 2 of the firmware.

Can anyone help an explain what's  causing this override and how I can fix the problem.

Thanks,

My lounge HR91 does the same! It is programmed to be 19c at 8am, but from 7.45 till 8am it sets itself to a whopping 35c. It is not scheduled like that at all.
And I noticed it just now as well. It’s programmed to a lower temperature from 9.30pm but at 9.15pm it also set itself to 35c! I heard the valve open all the way, so I quickly looked at the app and it said 35c before quickly changing to 19c on its own as I was looking at the screen.

I haven’t noticed it on any other HR91s. Really weird behaviour, and quite worrying.

I have exactly this behaviour on one of my HR92s. For no apparent reason it sets itself to 35C - the "optimum start" logo also shows on the main controller screen. The valve then fully opens. What I've seen is that this stays like this until the room temperature has exceeded the setpoint by a couple of degrees. It then turns itself off and sets the temperature to what I have in the schedule. Very strange. I've never seen it massively overheat the room (which is a bathroom).

While it is less of an issue in the morning, I do find it a big issue that the evohome decides my lounge needs to be set to 35c 10 minutes before it is programmed to drop to a lower temperature.
It happened again today: optimum stop is enabled, but at 9.20pm the valve opened completely, even though 10 minutes later the temperature would be dropped to a cooler overnight temperature. The lounge was already warmer than the normal scheduled temperature due to body heat etc, yet still evohome wants to give it a boost for 10-15 minutes.

It doesn’t do this during the rest of the day, just at the beginning and end and I just don’t get it. There is zero logic to this. I really don’t know what to think of this system right now.

Jimopg wrote:Hi,
I have just installed Evohome system with HR91 thermostats.
I have 9 zones.Everyhing seems to work OK except one zone.

I have a problem with one zone which has 2 radiators.
I  noticed the temperature in this zone was much higher than I had set on the schedule.
On looking on the display unit I noticed the target temperature was 35 C!

I did not set an override of 35 C.

This has occurred  a couple of times and the target temperature of 35C appears randomly even after I have cancelled it.
I have version 2 of the firmware.

Can anyone help an explain what's  causing this override and how I can fix the problem.

Thanks,

How have you paired up the zone? Is it only the zone with 2x HR91's you are having trouble with?

Again tonight: 8 minutes before a lower overnight temperature kicks in, evohome thinks it’s a good idea to set the lounge temperature to 35C. Absolutely ridiculous. This is WITH optimum stop enabled.

Sorry, can't help with your issue (too new to Evohome), but intrigued regarding how you produced that graph?

lloyd wrote:Sorry, can't help with your issue (too new to Evohome), but intrigued regarding how you produced that graph?

It’s generated by Home Assistant. It shows a 24h history from the evohome “entities” and you can use Home Assistant to integrate evohome into smart home routines with a whole bunch of other smart home devices.

I get the random temperature overrides on HR80s and MT4 valves connected via BDR-91. Blasts of 35℃ are the latest joy to experience.

My Gen 1 Evohome was pretty flawless, but the new Gen 3 controller seems to be riddled with bugs.

Nabys wrote:Again tonight: 8 minutes before a lower overnight temperature kicks in, evohome thinks it’s a good idea to set the lounge temperature to 35C. Absolutely ridiculous. This is WITH optimum stop enabled.

5EA3DF5F-08DE-4667-9E35-F770670852FA.png

Have you contacted Resideo support (0300 130 1299) and requested help? What firmware version are you on?