Remote override room setpoint no longer cleared
Posted: Wed Dec 08, 2021 11:04 pm
Last weekend, I got a new Remeha Avanta Ace boiler and Remeha iSense thermostat, but kept my OpenTherm Gateway with firmware 5.1. Both the boiler and thermostat implement OpenTherm v3.0 (my old Remeha Avanta boiler and Honeywell Chromotherm thermostat did v2.x), but the OTGW seems to work fine, except for one quirck.
When I set the remote override (TT=22), the behaviour is as before: after a couple of seconds the OpenTherm Monitor shows the Remote override room setpoint, and some time later, the Room setpoint has changed accordingly. The thermostat display shows the symbol for manual override. When the schedule resumes, the thermostat no longer shows the manual override symbol, and changes the room setpoint. This is reflected in the OpenTherm Monitor, but the gateway doesn't clear the Remote override room setpoint (reset it to 0).
The thermostat reads message 9 every seven seconds (which is more frequently than my old thermostat, if I remember correctly). The boiler doesn't support this message (checked by setting the gateway in monitor mode). The gateway intercepts the message (as far as I can tell: as it should), reading some other message from the boiler and returning the remote override room setpoint as set by TT. I think this is the same behaviour as before. When the schedule resumes, the gateway continues to return the previously set value.
From the OTGW documentaton: "The gateway will continue to send a setpoint override value until it detects that the thermostat no longer honors the change (probably because it was canceled by a manual action or by the thermostat schedule). When that happens the override room setpoint resets itself to 0.0."
How does the gateway detect that "the thermostat no longer honors the change"? I assumed this was because of the changed "Room setpoint"? The thermostat writes this message 16 every 42 seconds, and the boiler acknowledges these messages.
As a side note: the thermostat also tries to read messages 99, 109, 110, 111, and 112, but the boiler doesn't support any of these.
When I set the remote override (TT=22), the behaviour is as before: after a couple of seconds the OpenTherm Monitor shows the Remote override room setpoint, and some time later, the Room setpoint has changed accordingly. The thermostat display shows the symbol for manual override. When the schedule resumes, the thermostat no longer shows the manual override symbol, and changes the room setpoint. This is reflected in the OpenTherm Monitor, but the gateway doesn't clear the Remote override room setpoint (reset it to 0).
The thermostat reads message 9 every seven seconds (which is more frequently than my old thermostat, if I remember correctly). The boiler doesn't support this message (checked by setting the gateway in monitor mode). The gateway intercepts the message (as far as I can tell: as it should), reading some other message from the boiler and returning the remote override room setpoint as set by TT. I think this is the same behaviour as before. When the schedule resumes, the gateway continues to return the previously set value.
From the OTGW documentaton: "The gateway will continue to send a setpoint override value until it detects that the thermostat no longer honors the change (probably because it was canceled by a manual action or by the thermostat schedule). When that happens the override room setpoint resets itself to 0.0."
How does the gateway detect that "the thermostat no longer honors the change"? I assumed this was because of the changed "Room setpoint"? The thermostat writes this message 16 every 42 seconds, and the boiler acknowledges these messages.
As a side note: the thermostat also tries to read messages 99, 109, 110, 111, and 112, but the boiler doesn't support any of these.