It works in the beginning, even getting it to heat works, but after some time it (10-15 minutes) it stops working (OT conn loss). Was using the thermostats original wiring at first (close to 12-15m length) and tried it temporarily with a new cable (1m length) because i tried to rule it out that it was the cable, but gave the same result
Sorry for double posting, but i ment that my boiler has an optional OpenTherm module, which works fine with the original thermostat
hi all,
just installed the opentherm module and wanted to ask if this was normal behavior. I donāt know a lot about opentherm and iām still in the learning curve. I have a daalderop cube duo with floorheating.
max watertemp is set to 55 and low is i think 20 bot not sure. Room temperature is set to 18 degrees and itās now 19.7.
the system is now running for approximately 4 hours. let me now if you see some anomaly or something i need to pay attention to.
Hi there,
Could Opentherm monitor whether the warm water tap sensor is trigger t on a Intergas HRE? My current HoneyWell cant read that sensor and Itās needed for a current energy/money saving project. I donāt have the hardware jet, but if Opentherm can read this sensor I might prioritise this project.
Thanks in advance
Iām heading in the same direction for my setup. My Intergas HRE boiler can have 2 zones. So hereās my plan:
- Zone 1 - This is my living room, with floor heating, and it has a thermostat that uses OpenTherm to regulate the boiler.
- Zone 2 - The boiler can only have an on/off thermostat in this zone, so theoretically all I need is to send an ON signal when it should turn on, and OFF when off. I can use HA to determine when it needs to be on (when at least one of my TRVs are below the target temperature).
Question is, what signal does an on/off thermostat send to the boiler? Is it a signal, or is it just a circuit thatās completed. Anyone know?
If itās just a circuit, I can use any smart switch. If itās a signal, Iām going to need a board I guess.
Tips? Ideas?
Some boilers with basic thermostat need a live feed to turn on. Others need a loop closed (dry contact). Youāll have to check the type of boiler.
I found this which may help as it explains the difference between the two types in a smartphone sort of way (and how to mangle a sonoff into a dry contact smart relay)
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Seems the second thermostat connection in my boiler requires (0,1A-24Vdc), and it has to be an on/off thermostat (not OpenTherm). Iām no expert at electronics, but does this mean it MUST have 24V or it MAY have 24V? I still interpret it as if closing the circuit would be enough to work though. The manual doesnāt say much more than the above.
Iām not sure, I would use a multimeter/voltmeter on the thermostat connectors to see what the existing thermostat is sending and then replicate that.
The existing thermostat is an OpenTherm one, so that wonāt work, since that certainly sends some form of data as well. Iād need access to a ādumbā one to do so I guess.
Thanks! I got the same error once updating to HA 12.1.
Iām trying your config but I get an error on the climate setup.
The system cannot restart because the configuration is not valid: Invalid config for [climate]: required key not provided @ data['platform']. Got None. (See /config/configuration.yaml, line 38).Update HA to the laatest available version. If u had quite old one - you might need to do update several times.
P.S. We have updated or blog post on diyless to correspond new HA format. Should work for now.
@ankabout
Is that āzoningā managed by the boiler itself? Or you have any external device managing valves, etc? Because in the manual for Combi Compact
HRE 24/18 (G.C. 47-291-01)
HRE 28/24 (G.C. 47-291-02)
HRE 36/30 (G.C. 47-291-03)
HRE 36/40 (G.C. 47-291-04) boilers i just found:
All controls/ zones should be connected in an external wiring centre and a switched live connected to 1 on X2. Set in-built timer to C-ON.
Also, a warning
link in 6 - 7 of connector X4 must be removed
is there few times. And 6-7 are the contacts for dumb on-off thermostat, so im not sure if you can use both of them at the same time.
P.S. on-off thermostat is a simple relay, which shorts two contacts. Its called ādry contactā. Think of it as a mechanical switch. If you need automate it - use any smart switch or relay, just be careful to not feed mains through it to the boiler, that would fry boilerās brains instantly.
Thats why there is a piece of wire by default on these contacts, it represents āonā thermostat state. Providing manual says itās needed to remove it for open therm to work - there is a possibility that it wont work if simple thermostat is in āonā state. Your can easily check that by attaching opentherm thermostat, and see if it works with that wire across 6-7 and without it
Strange that boiler target temperature is oscillating so frequent. Would be nice to see if there are any errors. Is that diyless thermostat with xiaomi ble? Or just master shield and built in/mqtt sensor?
I send an average calculated room temperature value to the OT Stat. I then schedule the set point of the OT stat using an average of the different room set points throughout the day which seems to work pretty well.
I have shelly TRVs on the radiators which deal with the room set points separately and avoid overshoot in the individual rooms. With a towel rail and hall radiator without control to give expansion if all TRVs are closed.
I have a calculated max flow temp sensor which is calculated using an old school VT curve with input from an external temp sensor. Currently looking at pushing this back into the OT gateway to dynamically adjust the maximum flow temperature value.
Just got the DIYLess board a week ago so spent the last two hours reading all these posts! Hopefully I can add to the project.
Iām looking to pull out the return water temperature which I think shouldnāt be too difficult Iām hoping!
Hi @geronimobb , did you just set this up straight out of HA? Or have you altered the sketch to suit?
Cheers
Musicman
from HA. I use automation(s) where i publish something to these mqtt topics. Directly it is read (/ received) by the thermostat, which is using these mqtt topics.
Thanks, had a dig through the source code and worked out the differences.
The only issues Iām having is that I canāt seem to get the HA thermostat to send the values and the OT shield to keep them. In MQTT explorer I can see the set topic go over but the get topic never seems to match up! Any ideas?
In order for the ot shield to keep them, you have to repeat the messages send.
For the room temperature i use a ātime pattern triggerā automation with the message send once in 30 seconds (ā/30ā), same for the setpoint. Pay attention to the format of time pattern in home assistant!
For the state (heat / off) is use an state trigger automation, so no time based.
For the override topic, i use again a time pattern trigger automation, once every 5 seconds (ā/5ā), and activate or deactivate this automation from my dashboard. If i want to speed up the reset to normal working, i use a state trigger automation where i send a ā1ā to the topic. For this last one i use a button on the dashboard. This has off course only sense, if you disable the automation where you override the target topic.
Regarding the state of the ha thermostat, i think that maybe it is more logical to use the state_attr of your ha thermostat as trigger than the simple temperature difference (setpoint - room temperature). In your ha thermostat config you can choose the cold&hot_tolerance in a way that the modulating shield can do its job more easy. I choose it a bit higher, because i have overshoot sometimes during the first cycle.
I have recently purchased the ot diyless thermostat, but am unsuccessful at getting any readings.
I have an Ideal ESP1 35 Combi boiler. Section 2.18 INSTALLER WIRING of the service manual describes OT installation https://idealheating.com/uploads/documents/Logic-Combi-Esp1-Installation-And-Servicing-222353-1_inst.pdf. The high-voltage thermostat wiring is removed and the 2 cables are connected to the OT low-voltage side.
I have flashed the ESP with the code here GitHub - diyless/home-assistant-opentherm-thermostat: Home Assistant OpenTherm Thermostat and have added the configuration.yaml from post #156 by StimpyMGS.
The OT Climate card is available, I assume from the configuration.yaml file, but otherwise the ESP32 seems pretty lifeless. Any assistance appreciated.
EDIT: Definitely didnāt enter my SSID password wrongI 
Now the ESP is communicating correctly with HA it still appears the communication with the boiler still fails; in that all the values that would be generated by the boiler return 0.00C with the exception of OT integral error which returns 25.00
EDIT: The serial monitor output these message:
Current temperature: 15.00 Ā°C (internal sensor)
Error: Invalid boiler response 0
EDIT: I believe now the Invalid boiler response is because the boiler is not correctly setup for opentherm. There was a loop wire between the opentherm connectors and a connection for the mains room stat. I removed the mains room stat wiring and joined the connector block for opentherm. Still received the invalid boiler response error, but Iām hoping that was only because Iād not connected a loop wire to the room stat wiring as shown in the installation manual; in a similar fashion to how opentherm was wired.
TL;DR I think the wiring should be one protocol connected / utilised while the other is closed with a loop wire. Itās getting early, and will try again with a clear head tomorrow.
Can you show your wiring for now?
From the manual i see that by default your boiler has short wire on room and ot terminals.
Leave room terminals shorted and remove it from ot, and then connect OT master shield to opentherm terminals.
That leaves as is:
That should be removed before connecting to opentherm thermostat:
Also, youāve ordered a thermostat bundle (with xiaomi ble sensor) and soldered master, or just master shield itself? Maybe soldering joint is an issue?
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