Quote Originally Posted by blowlamp View Post
This is the wrong conclusion as far as I'm concerned.

As I've pointed out on a few occasions, connecting a more fully featured OpenTherm thermostat to a weather compensated Intergas boiler means that the boiler expects the thermostat to use its own compensation curve as well as its own maximum central heating temperature setting. The boiler just relays the outside temperature reading over to the thermostat so it can calculate a water temperature to send back to the boiler. It's then down to the boiler how it maintains that temperature.

My OpenTherm/weather compensated Intergas boiler & Remeha iSense thermostat combo works perfectly as above, as does the inlaws Intergas/Nest v3 setup configured as an OpenTherm installation.
You seem to be reading and responding to something that I didn't actually say.

I didn't even refer to weather compensation at all. I actually said "is it Evohome or Intergas responsible for the CH flow temperature control not functioning with OpenTherm control". This was in response to Kevin's remark "I learned that the boiler does not report the Max CH water setpoint set by the front panel but overriding this does influence the Control setpoint temperatures sent by Evohome."

So while Kevin was trying to implement weather compensation, along the way he discovered that the Intergas boiler in Opentherm mode does not send the CH max flow temperature setting from the front panel to the OpenTherm master, (Evohome) however when he intercepted and modified this value from the boiler Evohome did indeed respect this maximum flow temperature requested by the boiler in the flow temperature requests it sent back to the boiler.

For a long time Intergas and Honeywell have pointed fingers at each other but in my opinion this proves that the blame lies with the boiler not sending the CH max temperature setting to the Evohome.

That's all I was trying to say.