EvoHome open therm

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EvoHome open therm

Postby fraggel » Sun May 18, 2014 9:48 pm


Since a week I have the evohome system (color display) partly installed.
I have a display, an internet gateway and open therm module setup at this moment. Other parts are not connected yet.

At the evotouch, a single zone is installed in which the evotouch measures temperature.
Also the open therm module is linked. The signal strength when testing is 5 blinks, so that should be no problem.

Unfortunately, the heating does not start when temperature is set to 30 degrees Celsius for that zone.

When pressing the button on the open therm module, heating starts/stops (according to indicator on heater), so the heater is connected to the module correctly. But pressing the button is manual control, so not for normal use. After disconnecting the module, the evotouch unit indicates communication loss with the module, so communication really seems ok.

Should the evotouch indicate when heat is requested? Since I do not see any indicators for it.

Trying to resolve the issue, the evotouch display was completely reset and linked again to the open term module which was also fully reset. Unfortunately still no luck.

The module is connected to the heater (agpo econpact 27c) on pins 3 and 4.
Configuration is done by the wizard as well as by hand.

Does anyone have a clue what is wrong with this very basic setup?
I do not want to connect extra components until this works. I have read info about similar problems but this seemed to be the previous version of the device.

If more information is needed, don't hesitate to ask.

Thanks in advance for thinking along
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Re: EvoHome open therm

Postby emmeesse68 » Mon Jan 26, 2015 12:43 pm

Hi fraggel, did you have any luck with your issue? I have some more complex setup, having previously bound a couple BDR91 to drive my old-style motorised zone valves, and the R8810 actually activates my boiler (Ferroli BlueHelix Pro 32C combi condensing) but the issues are so many that I'm considering driving the boiler in on/off mode with a BDR91 and dump my R8810...

Mine seems to go nuts whenever:

- I use the hot water (just having a hot shower may make the heating stop responding, zone relays switching but boiler not firing)
- The boiler pauses the flame for having crossed temperature ilmits (I think) - this happens sometimes when the boiler is driven full power for a long time and room temperature approaches proportional band...

Can't figure out if the issue could be:
- the R8810 not properly communicating with the Evohome (even if it passes the comm test with 5 red blinks) - faulty R8810?
- the R8810 non communicating properly to the boiler itself (my OTG is on its way, I'm willing to investigate) - faulty R8810?
- the OpenTherm implementation of my Ferroli boiler doesn't match that of the Evohome system?

Does anyone have experiences to share using an R8810 OpenTherm gateway with Evohome new (color screen) and a combi (CH + DHW) boiler, maybe Ferroli? My boiler switches heating off when hot water is requested...

And... does anyone know of R8810 documentation (besides of the very minimalist installation guide included with the R8810 itself)?

Thanks a lot...

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