Buderus GB162 boiler - compatibility ?

[Sungray]

Hi,

I want to use the Loxone Smart Heating with a Buderus GB162 boiler. Is that possible ?

They want to install a RC300 thermostat for floor heating ground level and RC200 for radiators at the 1st floor. I want to use Loxone instead. How can I achieve that ?

Thanks !

[Lepelrekje]

Identical setup here. I've been looking for a solution, but none found so far.

Anyone found a way to do this?

Thanks!

Op maandag 25 januari 2016 16:21:44 UTC+1 schreef Sungray:

[TomM]

I don't know anything about these boilers but I assume they are like any other boiler that takes a signal (12v or 240v or similar) to tell it to activate.  Therefore all you require is a simple relay to send the required voltage to activate the boiler when you want it turned on.  this could be in the form of a digital output from the miniserver or even a DMX channel output.

If it accepts a variable voltage level to regulate the energy output then you could consider using an 1-10V output on the miniserver or a DMX dimmer channel to achieve this depending on the exact requirements.

You will of course have to connect up all the associated valves and pumps to have them controlled by loxone too but thats all pretty straight forward once you get started.

With regards to thermostat, you can use any appropriate temperature sensor with input into the miniserver - the most popular solution probably being 1-wire.  The miniserver will then do all the hardwork that the thermostat would normally do.

Unless I've missed something fundamental about these boilers which means they can't be controlled in this manner, this should get you started on the right path.

[Sungray]

I'm late in my answer but here it is.

Apparently those Bosch/Buderus/Nefit boilers are completely closed. For communication they use a closed up bus (EMS). You actually cannot send any command to it or activate it via relay or whatever. There is no solution.

I would never have bought this boiler had I known this.

I'ver been messing with this https://github.com/bbqkees/Nefit-Buderus-EMS-bus-Arduino-Domoticz to try and send commands, but it's just too messy. The boiler doesn't want commands hammered into it. It will go back to using thermostat commands as soon as it can, and if you try to command the thermostat instead, it will go back to it's own routine asap.

Anyway, I hate this, but I have no solution, it's infuriating.

[Duncan]

according to this manual - https://www.buderus.co.uk/files/201111151248190.tech-and-spec-for-gb162.pdf

the boiler has a connector for potential free on/off relay control - this could then be used by loxone

the WA connector (purple) on page page 12 would apprear to do what you require.

[Sungray]

Hi Duncan,

Thanks for your insight. Problem is I have two circuits, or loops, one for each story. To deal with this I have two thermostats and two MM100 modules : https://www.bosch-climate.com.au/files/mm100_installation_manual_AU.pdf

Those modules are, basically, a pump + mixing valve, to allow differenciated temperatures in the two circuits.

The perfect things would be to disconnect the thermostats, plug loxone into the on/off relay control of the boiler, and have a way to control the temperature and the pump of the MM100 modules. I haven't found how to do this but maybe it's possible ? What do you think ?

[Duncan]

if you want to go to the trouble of using loxone to control this system directly it can be done, but you will have to open the MM100 modules, disconnect or remove the existing electronics and connect loxone to the pump (240v relay/ssr), the 3 port mixer valve (240v relay or ssr), and add a temperature sensor to the output pipe eg 1-wire, then use a loxone mixing valve controller block to manage the temperature control of the mixer/mm100 mechanicals

depends on your appetite for hacking!

[Sungray]

:( my appetites are not that skilled unfortunately. Also I'd like to keep the possibility to just replug the thermostats in case of failure.

But in the doc of the MM100, I can see these connectors

MD1 :  Volt free contact for constant heating circuit: external signal for heat requirement (-) – heating pump on/off (-> additional accessories)

VC1 : Mixing valve actuator connection (valve circuit): Terminal 43: mixer open (for warmer heating; for cooler cooling (cooling function) Terminal 44: mixer closed (for cooler heating; for warmer cooling (cooling function)

I don't suppose this is usable by Loxone ...?

[David Wallis]

had 2 mins to do a bit of googling and it doesnt appear that it uses the opentherm protocol.. however it suggests that the CT100 thermostats can be controlled remotely... then digging into that you come accross.. https://community.openhab.org/t/will-there-be-a-bosch-smart-home-binding/8910/25

so it may be possible but its not going to be simple.. so back to a relay unless you want some work!

[Duncan]

the pc1 goes to the pump, and vc1 goes to the 3 port actuator

both of these are 240v - it looks like you could turn off the power to the mm100 and just attach cables to the pc1 and vc1 to provide 240v via loxone controlled outputs - that would give you direct loxone control over the pump and mixer -just add an output temperature sensor (clip one to the output pipe) and you should be good to go, and easy to return to normal in the future.

alternatively, with the unit powered up, looks like you can use the mc1 input (zero volt) to trigger the pump on/off, but then you still need to control the mixer valve externally, and you dont want any conflict with the mm100 internal control. if the config switch is set to 0 then perhaps the mc1 will still work and you could power the mixer directly through the vc1 connector

[Sungray]

Hi Duncan,

Sorry about the probably stupid question, but I don't understand how to make this potential free relay work. Should I plug it simply to a digital output ? I'm afraid of doing something bad.

Thanks

[Duncan]

you just need the 2 contacts of a loxone relay connected to the potential-free input 2 contacts - when the 2 input wires are shorted together by the relay then the boiler will fire up - just dont connect any wires to it having any voltage, not 24v from loxone and definately not 240v as you will kill the boiler

[Sungray]

Just tested and the circuit breakers of the whole system tripped (not the loxone one) when I switched the relay on ? Nothing burned fortunately, but what did I do wrong ?

It's just a wire running from the potential free of the boiler to the relay (digital output)...

[Sungray]

Okay found out why, I forgot that I've serialized the neutrals... Ever tried shorting a serialized circuit ? Well let me tell you it doesn't work very well

[Gábor Bungyi]

Hi All,

may I ask, if you got to any solution here?

I have two circuits too and want to overrule it via Loxone.

Thanks

G.

[L P]

I have a Buderus geothermal heat pump (WPS9) with no provisions for external controls. But... It has a switch that allows an external system to change the setting of the system between two states: (1) Hot water for home use only and (2) Hot water for both home use and and (underfloor) heating. The heat pump came with its own thermostat, which is in the garage with the rest of the system. I set the thermostat in the garage to 30C so that it will always trigger the heating. I have KNX thermostats, but all they do is report to Loxone and I use the Intelligent Room Controllers for each heating zone. If any one of the heating zones demands heat, it triggers a relay with activates mode (2). This is a roundabout way to integrate the systems, but it has been working well for 10 years so far. Check and see if your boiler has a relay that can be used to trick it into what you want. Attached is the electrical connection diagram from the manual for your boiler, maybe something there can be used.

https://www.bosch-homecomfort.com/us/media/country_pool/documents/download-buderus-products/buderus-manuals/gb162_installation_instructions_en_us.pdf