Transform OT commands on the fly?

[peterfarkas]

Hi All,

Apologies if my questions are basic, I tried to educate myself as best as I could before raising this.

Is the OTGW capable of receiving OT commands from a thermostat and transforming them on the fly?

Eg. I want to change the command which is sent to the boiler by the thermostat. My thermostat is sending incorrect values to my boiler and if I could have OTGW in the middle, this could be a viable workaround.

Background in case you are interested:

I have an issue where a Honeywell Evohome R88 OT gateway is unable to control my Vaillant boiler (equipped with the V33 ebus - OT interface card)

I have a Honeywell HCC100 underfloor controller (newer version of the HCE80 zone controller), which has its own opentherm output to control the boiler. And it can control it beautifully.

However, I have non-underfloor zones as well, so I need to control the whole system through Evohome and the R88 OT gateway. And the R88 gateway is unable to control the boiler. It starts the pump, and the display shows the maximum flow temperature set on the boiler, and the burner itself never fires. So it just circulates cold water in the system, while Evohome thinks that the heating is on.

My plan is to obtain an OTGW, understand how the correct commands look like when they are sent by the HCC100, and then hook the boiler up to the R88 and transform its messages so the boiler can execute them correctly.

[hvxl]

Have you read http://otgw.tclcode.com/? Then it should be clear that transforming certain messages from the thermostat to the boiler and back is actually one of the main purposes of the OTGW. The gateway firmware only provides commands to modify some common messages. If that is not sufficient for your needs, you can switch to the interface firmware. That gives you full control over each message.