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Searching for good RF thermostat

PostPosted: Tue Aug 28, 2018 6:57 pm
by Cooter

Until now I used the OTGW with a Honeywell touch modulation in combination with a Siemens PLC. The PLC controlled the boiler completely.

Now I have moved to another house and am forced to use a wireless (RF) thermostat.
The thermostat in the new house is a Honeywell wireless. I can connect this directly to the boiler via RF.
But the boiler does not transmit thermostat data to the OTGW. So then I bought a Honeywell opentherm RF module to connect to the OTGW.
Now I can read thermostat data. But unfortunately it always sends the room temp as 20C.

So now I am searching for a RF thermostat which can send the actual room temperature and setpoint in a decent accuracy (0.1C) and frequency.
Every 2 or 3 minutes new data would be ok.

According to the thermostat OTGW matrix the Honeywell Wireless modulation should work.
Can someone tell me how the Honeywell Wireless modulation responds?

Other options are also welcome.

Re: Searching for good RF thermostat

PostPosted: Wed Aug 29, 2018 8:15 am
by Cooter

Can you please send me a logfile of a Honeywell wireless modulation?
Then I can see how often the room temperature is send by the thermostat?
Because this is crucial for a good boiler control.



Re: Searching for good RF thermostat

PostPosted: Thu Aug 30, 2018 8:54 pm
by hvxl
I didn't ask the people who uploaded their logs for permission to share the raw source with others. So I don't want to do that.

However, looking at logs tagged as being made with a Honeywell Wireless modulation, I believe this thermostat doesn't report realistic room temperature values. In one log, spanning over 12 hours, the thermostat consistently reports a room temperature of exactly 20.00 degrees.

Another log only covers 43 minutes. In that log, the room setpoint and room temperature both start out at 20.00 degrees. When the setpoint is raised to 23.50, the room temperature immediately jumps to 22.61. The room temperature of a normal house can't make jumps like that.

In both logs, the thermostat doesn't tell the boiler to start heating when the setpoint is raised above the reported room temperature. So I have to conclude that the room temperature and/or room setpoint values are fake.

In case you are still interested: The room temperature is reported about once every minute.

Re: Searching for good RF thermostat

PostPosted: Fri Aug 31, 2018 10:22 pm
by Cooter
Ok then the Honeywell wireless modulation is no option.
My previous Honeywell touch modulation was also faking room temperature on the display when you are changing setpoint.

So no I am thinking about a Remeha I sense RF. Remeha also has better temperature accuracy on display as I recall from a celcia20.
Do you have any logfile information about the Isense RF, HVXL?

Honeywell Lyric T6R is also an option but I don't like the power cord that is needed.

Re: Searching for good RF thermostat

PostPosted: Sat Sep 01, 2018 7:42 pm
by hvxl
I suspect many battery operated RF thermostats won't report the actual room temperature. Transmitting data uses battery power and boilers generally don't have a need to know the room temperature. They are controlled via the control setpoint. So, skipping this information on the RF interface makes the batteries last longer. To be able to use the same opentherm routines in the base unit as used in a wired thermostat, the base unit may just transmit some default value. If that suspicion is true, you may have a hard time finding an RF thermostat that fulfills your requirements.

As you can see in the equipment matrix, the iSense RF is not listed. That means nobody has uploaded a log file for it.

Re: Searching for good RF thermostat

PostPosted: Sat Sep 01, 2018 8:40 pm
by Cooter
The isense RF is listed. After the ICY.
Altough not as Remeha. Ik assumed it was a Remeha.

If your theory is true about saving battery then I might indeed have a problem finding one.

In that case, a rf thermostat with power cord, has no reason not to send the room temp like a wired one.

Re: Searching for good RF thermostat

PostPosted: Sat Sep 01, 2018 10:41 pm
by hvxl
OK. That log is one hour long with only 4 room temperature reports. So on average once per 15 minutes, although they are not evenly spaced. But they do show believable values.

Re: Searching for good RF thermostat

PostPosted: Thu Sep 06, 2018 1:17 pm
by Cooter
Thank you. 15 minutes between updates is still not ideal.
Can you please give me the update time of roomtemperature of a Honeywell lyric T6r?

This one has a power connection.

Re: Searching for good RF thermostat

PostPosted: Fri Sep 07, 2018 9:01 pm
by hvxl
The only log file I have that was tagged as Honeywell Lyric T6R is only 8 minutes long. The room temperature is reported every minute. However, the first 5 minutes the exact same temperature is reported every time. Then it jumps 0.22 degrees and that temperature is then reported for the remaining 3 minutes. So, even though the temperature is reported every minute, I doubt whether those are always new measurements.

Re: Searching for good RF thermostat

PostPosted: Sat Sep 22, 2018 12:53 pm
by hvxl
I recently received another log file made with a Honeywell Lyric T6R. It doesn't contain MsgID 24 at all during a period of more than an hour.

Re: Searching for good RF thermostat

PostPosted: Fri Nov 30, 2018 1:20 pm
by Cooter
I also noticed that the room temperature seems to change in steps of 0,21 C. That is ridiculous.

Re: Searching for good RF thermostat

PostPosted: Fri Nov 30, 2018 1:23 pm
by Cooter
I also tried a Nefit Easy. Unfortunately it does not send MsgID 16 (room setpoint) and 24 (room temperature). Which makes it useless for me :?

Re: Searching for good RF thermostat

PostPosted: Tue Dec 11, 2018 8:20 pm
by Sky
I have a Lyric T6 installed (so the wired one), combined with Remeha Calenta Ace.
The Lyric writes a Room setpoint (msg 16) as well as a Room temperature (msg 24) every minute.
Room temperature is changing in 0,21 °C steps as already reported in other posts.
Control setpoint (msg 1) is sent every minute.