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Hi,

Unfortunately I think you're unlikely to find any information which clearly indicates compatibility and Glow Worm don't officially support Opentherm. Even with my Ultracom2 I had to just rely...

I think Paul's correct about S4. Google came up with this Dutch manual which labels S4 as the 'Cold water sensor' i.e. flow-in from a pre-heater (Solar Water Heater in this example)....

Yes, just using the HR92s should work OK. I use 16 of the HR92s split into 12 zones without any additional thermostats etc and they work perfectly.


I self-installed my Evohome system in a large...

Yes, it's the optimised start symbol. Here's a link to a helpful document on the Honeywell website which describes all the icons (the second file gives the ones for the newer firmware which includes...

Hi Richard,

I've had a quick search and found a few pictures of the card from your boiler and it's not the same as the one in my Ultracom2. The pictures I found look almost identical to the card...

Thanks for highlighting this work in Home Assistant. It's been a while since I looked at it and it's great to see that there are plans to add HGI80 support. I'm going to reach out to the developer...

A partial solution to Phase 4 which you may already be aware of is the 'Nefit EMS-OT OpenTherm converter' described on this page:

https://myboiler.com/opentherm/worcester-bosch-opentherm/

It's...

My preference would be to retain the Honeywell controller which would still handle system set-up and the background system control, and add a device with neater interface for monitoring and control. ...

Yes, that's correct. The heat demand isn't available via the API, only via one of the controller menus or using a HGI80 type device to monitor the Evohome wireless messages.

Sorry, I should have added some further details. On the controller, if you press and hold on the settings button you get to a menu labelled 'Installer Menu'. If you click on the 'System Summary'...

No, not via Evohome as it only tells you what it has asked the boiler to do, but not the actual boiler status. It is possible to monitor some boilers remotely via Opentherm or other serial...

The only comments I can add are that my experiences with the use of the Evohome controller as a room temperature sensor have been positive. You also have the option to use the temperature sensors...

I don't think these 40min no heat periods will mess up the Evohome controller's 'fuzzy logic' heating optimisation algorithm. My confidence is due to the fact that even with standard gas boilers...

Thanks for the additional info on how the 40min periods are spread throughout the day. I'd wrongly guessed that more of them would be grouped together near times if highest demand e.g evening. I...

I was thinking that the room temperature might drop during some of the 40min periods so that you notice it feeling cooler. If this happens you could increase the setpoint by 0.5deg to keep the room...

I think the controller will work OK and the 40min periods won't cause it problems. It's a shame that the Evohome 6 setpoint daily limit isn't enough for your setup. I find the Evohome system works...

Oh, I didn't realise that you already had some of the Evohome devices!

I think I may have misunderstood exactly what you wanted the Evohome system to do.

Here's what the Evohome system should...

@Stevedh

There's quite a bit more detail on how the TRVs work on the Hive community forum:

https://community.hivehome.com/s/question/0D50J00005ATP7WSAX/-hive-post-important-faq-regarding-trvs-...

Yes, the c++ code is very modular and it can take a very, very long time to hunt down the exact details of command structures.

Hopefully the example timed setpoint override with decode below...

From your description of the problems it sounds like it's due to the messages sent from the controller not being received by the devices which would suggest that the problem is at the controller end....

Hi,

I've self-installed my Evohome system with a gas boiler, so I'm not an expert. The BDR91s are used as switch controls for devices like valves and to provide boiler control (connected to its...

Yes, I think you've come to the correct conclusion. Unfortunately, Evohome isn't designed to control the boiler to the extent that you need. It can provide separate heating and hot water control...

Good idea, but no, the 3 bytes at the end of these shorter 7 byte messages always seem to be FFFFFF. The timed overrides are sent in longer 13 byte messages using the same command 0x2349. Most of...

Oh, I see what you mean. Sorry, you can ignore the specific first device ID and any 18:XXXXXX value should work with your nano serial device (obviously if you're using a HGI80 you must use 18:730). ...

Here's some info on the command structure for sending an immediate setpoint override to zone via a serial device which we've decoded:



Example setpoint override message (command 0x2349):
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