Equipment details

While shopping for Opentherm equipment with home automation in mind, it can be useful to have some idea to which extent boilers and thermostats support the opentherm protocol. Only some messages are mandatory (ID's 0, 1, 3, 14, 17, and 25), all others may or may not implemented. (Yes Daalderop, support for MsgID 14 is mandatory.)

For home automation it is important to buy a thermostat that supports MsgID 9 (Remote override room setpoint) and possibly MsgID 100 (Remote override function). It may also be nice to get a boiler that supports MsgID 18 (CH water pressure).

Unfortunately this type of information is not usually provided by the manufacturors. That's why I started compiling a matrix with information extracted from logs of the opentherm communication between thermostats and boilers provided to me by Opentherm Gateway owners.

Of course, the fact that equipment returns a value for a certain MsgID doesn't always mean it really supports it. For example, I have heard that the Intergas boiler may respond to MsgID 18 (CH water pressure) with a value of 6. Clearly that is totally bogus. The valid range of values is only 0 to 5. 6 bar would definitely not be good for a central heating system.

Another example: the Remeha iSense sends MsgID's 20, 21 and 22 with its current time and date information, but it ignores whatever values it gets back in the response, unlike the Honeywell chronotherm IV. As a result, the Opentherm Gateway is not able to change the clock on an iSense thermostat.

For the reasons mentioned above, I obviously cannot give any guarantees on the information provided below. It's a best effort attempt to provide some more details on Opentherm equipment than are readily available from other sources. However, I can not be held responsible if information in these tables turns out to be less than accurate.

If your equipment is missing from the tables below, please add it by uploading an otmonitor log file.

Clarification of the tables

  • A bullet (●) next to a DataID in the thermostats table means the thermostat has been observed to send the specified DataID.
  • A bullet (●) next to a DataID in the boilers table means the boiler responded with a Read-Ack or Write-Ack message to a request from the thermostat for the corresponding DataID.
  • A cross (×) means the boiler responded with an Unknown-DataID message to a request from the thermostat for the corresponding DataID.
  • A question mark (?) indicates that logs have been uploaded with conflicting results for the DataID.
  • If there are very few bullets listed for a boiler, that does not necessarily mean that the boiler has very limited Opentherm support. If there are also very few crosses, the boiler was probably used with a thermostat that doesn't send many different Opentherm DataID's. Only a large number of crosses indicates poor Opentherm support by the boiler.

Boilers

 
AGPO Econpact 127C
Agpo Ferroli Econpact 225c
Atag A244EC
ATAG E325EC
Baxi Main Four 240 F
Baxi Nuvola 3 Comfort
Baxi Nuvola DuoTec HT 24
Bosch HRC 30
bosch HRC35/2
Brink Allure B25 HR
Brötje WGB 2
Bulex FAS
Daalderop Combifort
Elco Thision 9
Elco Thision 25
Ferroli BlueHelix Pro
Ferroli BlueSense 5
Ferroli Megadens
Geminox THRi 5-25 DC
Geminox THRi 2-17 DC
Geminox ZEM 2-17C
Hitachi RWM-2.0FSN3E
Hoval TopGas Comfort 16KW
Intergas Kombi Kompakt HR
Intergas Kombi Kompakt HR (36/30)
Intergas Kombi Kompakt HRE A 28/24
Intergas Kombi Kompakt HReco
Intergas Kompakt Solo HRE
Intergas Prestige CW6
Itho Daalderop Base Cube
Nefit Proline NXT HRC 24/CW4
Nefit Smartline (HR) + EMS-OT
Nefit TopLine Aquapower + EMS-OT
Nefit TopLine Aquapower HRC 45/CW6 + EMS-OT
Nefit TopLine Compact HRC25 + EMS-OT
Remeha Avanta
Remeha Calenta
Remeha Quinta 28c
Remeha Quinta 35c
Remeha Quinta 45
Remeha Quinta Pro
Remeha Tzerra
Remeha W28 Eco
Techneco Elga (+ Remeha Calenta)
Termet Ecocondens 30 1F (WKJ1301000000)
Vaillant EcoTEC CW5+
Vaillant hrSolide C
Vaillant VHR NL 24-28C
Viessmann Vitodens 100-W
Viessmann Vitovent 300
Windhager BWE 100 Exklusiv Bj2006
0 
1 
2××   ×     ×××    ? ×        
3×     ××          
4            ×          ×                           
5              ××××      
6   ××    ×××        
7                       ×                         
8                    ×                           
9 ×××× × ×× ××  ×      × ××  ×  ×××××    ××× ××  
10  ××  ×× ×          × ××        ×            
11                       ×           ×               
12  ××    ××           ×  ×        ×        ×      
13                       ×                           
14    ×× ×××××     ×
15         ×           ×   ×     ×××         ×  
16××  ×××××××× ×  ×  ×× × ×
17  ×××? ×
18       × ×  ×      ×  × ×
19   ×      ×  ×× ××× ××       ××  × ×     ×   ×  
20 ×   ×         × × ×         ××   ××      ×  
21 ×             × × ×          ×   ××      ×  
22 ×             × × ×          ×   ××      ×  
23          ×     ×  ×                           
24×××× ×××?××× ×××××× × ×
25   
26   × ×    ×       
27××   ×         ×    ×   ×   
28    ×××××      ×× × ×
29××       × ×××   ×××  × ×        ××××         ×  
30          ×         ×  ×                           
31               ×  ×                          
32                      ×                           
33                  ×                           
35                                  ×               
36                                   ×               
48   ××   ×       ×       
49            × ×      ×       
50                       ×                           
56  ?××   ×  ×    
57 ××× ×××××××××   ×
58                       ×                           
59                                                  
63              ×             ×                  ×  
70        ×              ×             ×            
71        ×              ×                          
72        ×              ×                          
74  ×     ××             ×  ×                       
77                                                  
78        ×              ×                           
79        ×              ×                           
80                                                  
82                                                  
86  ×     ××             ×  ×                        
87  ×     ××             ×  ×                        
88  ×     ××             ×  ×                        
89                                                  
90  ×     ××             ×  ×                        
98                                                  
99 ×    ×                  ×          ×           ×  
100 ×××  × ×× ×           ×     ×   ×××     ×××  ×  
109 ×                       ×        × ×   ××      ×  
110 ×                       ×        × ×   ××      ×  
111 ×                       ×        × ×   ××      ×  
112 ×                       ×        × ×   ××      ×  
113                             ×                   
114                                                 
115                     ×           ×              
116 ××  ××     ×       ×× ×       ×  
117  ×  ××                ×     ×    × ×        ×  
118  ×  ××                ×     ×    × ×        ×  
119 ××  ××     ×       × ×   × ×       ×  
120 ×  ××     ×       ×× ×       ×  
121 ×  ××             ×     ×    × ×        ×  
122 ×  ××             ×          × ×        ×  
123 ××  ××     ×          ?    × ×       ×  
124 ××     ×× ×          × ××        ××   ××         
125  ×     ××            × ××                   
126××    ×××× ×  × ×××     ××××× ××  ×    × 
127××    ××××    × ×××××        ×    × 
128                    ×             ×             ×
129                                             
130               ×                             ×
131                                  ×             ×
132                                   ×             ×
133                                   ×             ×
134                                                  ×
135                                                  ×
170            ×                                      
255              ×             ×      ×              

Thermostats

 
AgpoTherm Plus Artikelnummer: 1201045
ATAG Wize
Baxi 7104336
Baxi Nuvola 3 integrated
Bosch TF30
De Dietrich AD289 iSense
Ferroli Romeo clock thermostat
Google Nest V3 Opentherm
Honeywell Basicstat Modulation
Honeywell Chronotherm Modulation CMT937
Honeywell Chronotherm Modulation CMT8851A1006
Honeywell Chronotherm Modulation CMT8851M1000
Honeywell Chronotherm Touch
Honeywell Chronotherm Touch Modulation
Honeywell Chronotherm Vision Modulation
Honeywell Chronotherm Wireless Modulation
Honeywell EvoHome with R8810 OT Gateway
Honeywell Lyric T6
Honeywell Round Modulation
Honeywell Round Modulation T87M1003
Honeywell Round Wireless RF (Y87RF1004)
Honeywell Round Wireless RF (Y87RF2008) new model!
Hoval TopTronic-T/RS-OT
ICY Smart Thermostat
iSense RF
Itho Daalderop Spider
Quby (Toon)
Remeha c-Mix Regelmodule + 2x Remeha iSense
Remeha Celcia 20
Remeha iSense
Remeha iSense v19
Remeha iSense v27
Remeha iSense v28
Remeha Qsense
Siemens QAA73
Termet CR 11011 (WKZ0 624000000)
Theben RAM 850 top2
Viessmann Vitovent 300 controller
Windhager REG 021A, Theben RAM 786
0 
1 
2              
3          
4                                     
5        
6                        
7                                     
8                                      
9               
10                          
11                                     
12                                
14         
15                                
16     
17     
18              
19                              
20                             
21                               
22                               
23                                      
24    
25   
26         
27      
28                  
29                            
30                                      
31                                     
32                                      
33                                      
35                                    
36                                      
48                 
49                    
56       
57      
63                                     
70                                     
71                                     
72                                     
73                                      
74                                    
77                                      
78                                      
79                                      
80                                      
82                                      
86                                     
87                                     
88                                     
89                                      
90                                     
98                                      
99                                
100                        
109                                
110                                
111                                
112                                
113                                   
114                                    
115                                 
116                           
117                                    
118                                    
119                            
120                          
121                                   
122                                    
123                            
124                             
125                              
126                     
127                 
128                                  
129                                      
130                                     
131                                   
132                                    
133                                    
134                                      
135                                      
170                                      
190                                      
255