Thanks for your reply, DBMandrake.
I’m giving details of my setup that you may already be aware of in the hope they might be of use to you & others
My system is an Intergas boiler with Remeha iSense controller-thermostat. The sytem uses OpenTherm and weather compensation control together, the weather compensation sensor being wired directly to the boiler.
If no additional OpenTherm boiler controller-thermostat is connected, then the user adjustable weather compensation curve programmed into the boiler is utilised, provided it is sensed that an outdoor sensor is in-circuit.
However, when an additional OpenTherm boiler controller-thermostat is used, the weather compensation curve programmed into the boiler is ignored and instead, the one within the connected controller-thermostat is used, if available and it is sensed that an outdoor sensor is present.
The boiler passively sends the iSense the outside temperature value and from it, the iSense calculates a flow temperature to suit the current indoor temperature & weather conditions, which it returns back to the boiler. The boiler now only has to maintain that temperature according to its inbuilt logic and until the next request from iSense.
The iSense has a definable maximum flow temperature. There is also a Room Temperature Effect (RT Effect) setting, which deviates flow temperature from the programmed weather compensation curve, depending on how far away the measured room temperature is from set point. This effect is user adjustable and governs how high the boiler must fire to achieve set point.
The weather compensation curve of iSense is usually based on a set point of about 20C and is raised or lowered in relation to the actual requested set point. The default curve might be programmed to give a room temperature of 20C when it’s 6C outside with a flow temperature of 50C, whereas a room temperature of 22C whilst at 6C outside might dictate a 60C flow temperature. The RT Effect setting will also combine to shift the curve higher or lower along its temperature scale.
So iSense is quite unlike Evohome in many ways, but a major difference to me is that there is no ongoing learning required. In effect iSense is taught about the property it inhabits when the weather compensation curve is adjusted and other parameters are set. Also, because of the weather compensation curve, higher than necessary flow temperatures are very, very much reduced.
Martin.
I’m giving details of my setup that you may already be aware of in the hope they might be of use to you & others
My system is an Intergas boiler with Remeha iSense controller-thermostat. The sytem uses OpenTherm and weather compensation control together, the weather compensation sensor being wired directly to the boiler.
If no additional OpenTherm boiler controller-thermostat is connected, then the user adjustable weather compensation curve programmed into the boiler is utilised, provided it is sensed that an outdoor sensor is in-circuit.
However, when an additional OpenTherm boiler controller-thermostat is used, the weather compensation curve programmed into the boiler is ignored and instead, the one within the connected controller-thermostat is used, if available and it is sensed that an outdoor sensor is present.
The boiler passively sends the iSense the outside temperature value and from it, the iSense calculates a flow temperature to suit the current indoor temperature & weather conditions, which it returns back to the boiler. The boiler now only has to maintain that temperature according to its inbuilt logic and until the next request from iSense.
The iSense has a definable maximum flow temperature. There is also a Room Temperature Effect (RT Effect) setting, which deviates flow temperature from the programmed weather compensation curve, depending on how far away the measured room temperature is from set point. This effect is user adjustable and governs how high the boiler must fire to achieve set point.
The weather compensation curve of iSense is usually based on a set point of about 20C and is raised or lowered in relation to the actual requested set point. The default curve might be programmed to give a room temperature of 20C when it’s 6C outside with a flow temperature of 50C, whereas a room temperature of 22C whilst at 6C outside might dictate a 60C flow temperature. The RT Effect setting will also combine to shift the curve higher or lower along its temperature scale.
So iSense is quite unlike Evohome in many ways, but a major difference to me is that there is no ongoing learning required. In effect iSense is taught about the property it inhabits when the weather compensation curve is adjusted and other parameters are set. Also, because of the weather compensation curve, higher than necessary flow temperatures are very, very much reduced.
Martin.
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