Evohome + Opentherm v Evohome + Boiler Outside Weather Compensation

[HenGus]

B-M. I am afraid that I left the installer to do that bit on his own so I can't help - sorry.

[paulockenden]

Having now followed Paul's advice and deleted the CH wireless relay etc, I am now even more confused. There is now no mention of anything to do with the boiler in the System Menus - so no settings for boiler cycle rate, minimum time etc. Both HW and CH are working fine.

With an s-plan system, conventionally wired, there is no control over cycle rate, minimum on time, etc.

You only get those with a boiler relay. it's a silly limitation, really. I can't see any reason that we can't have those parameters, even when the boiler is being fired off the back of the control valves.

[HenGus]

With an s-plan system, conventionally wired, there is no control over cycle rate, minimum on time, etc.

You only get those with a boiler relay. it's a silly limitation, really. I can't see any reason that we can't have those parameters, even when the boiler is being fired off the back of the control valves.

Thanks Paul. I learn something new every day about this system.

[bruce_miranda]

Just looked at Richard's video for the Hot Water kit and clearly saw that a new menu appears only after the HW sensor has been paired (so I definitely need that). It then shows how the two BDRs are paired.

I think for people who don't use the HW kit you can use the Boiler Demand Wireless Relay in the System Devices menu to trigger the CH zone valve so that it opens whenever there is Heating demand. The zone valve can then trigger the boiler via a wired connection in the junction box.

OK so (Finally) back to Opentherm!

Can I use the Hot Water configuration menus to open up the HW or CH zone valves as required. And then let the OpenTherm bridge handle the Boiler firing independently to the zone valve openings.

[The EVOHOME Shop]

OK so (Finally) back to Opentherm!

Can I use the Hot Water configuration menus to open up the HW or CH zone valves as required. And then let the OpenTherm bridge handle the Boiler firing independently to the zone valve openings.

Exactamondo!

[bruce_miranda]

Brilliant.

So 4 pages of posts only to realise that Honeywell have put the S Plan HW/CH zone valve configuration under "Hot Water" which doesn't appear until you actually have a HW sensor!

[roydonaldson]

Yeah, EvoHome really needs some deployment application notes created for it. The guide it comes with is really bad, it shows you how to configure stuff, it has the diagrams for the different system types, it tells you there is guided config.

But, no where does it actually link any of the above together.

I should have app notes for deployment, ie. In a S-Plan system, do a factory reset, then enter Guided config, select Hot Water and then 2 2-port Valves and bind BDR91's. Do all this with pictures on it and then show a picture of the System Status menu to show what it should look like when done.

[paulockenden]

I think the options are there in Guided Configuration, aren't they?

But the supported S-Plan configuration includes the how water sensor.

I'm not surprised that you hit problems if you don't follow the book.

[top brake]

Yeah, EvoHome really needs some deployment application notes created for it. The guide it comes with is really bad, it shows you how to configure stuff, it has the diagrams for the different system types, it tells you there is guided config.

But, no where does it actually link any of the above together.

I should have app notes for deployment, ie. In a S-Plan system, do a factory reset, then enter Guided config, select Hot Water and then 2 2-port Valves and bind BDR91's. Do all this with pictures on it and then show a picture of the System Status menu to show what it should look like when done.

the notes you describe are available as part of the online training course? they are certainly provided on the face to face installer training course. please bear in mind that evohome is fundamentally a product for professional trade installers.

evohome can be applied in a variety of ways and as long as you follow guided configuration (and crucially answer the questions carefully) and refer to section 3 of the manual to bind the devices all should become clear.

hope this helps explain why the product is the way it is.

[top brake]

Brilliant.

So 4 pages of posts only to realise that Honeywell have put the S Plan HW/CH zone valve configuration under "Hot Water" which doesn't appear until you actually have a HW sensor!

I did my best to try to explain this at post #53